'Yes. He always called Dr Grimaud the Governor; n.o.body else had the nerve to; except Burnaby, and he calls him Pop ... So we said, "Righto," as you do, and didn't bother any more about it. We both sat down again. But I noticed that it was getting near ten o'clock, and I began to be watchful and jumpy, now that it was coming towards ten o'clock -'

Hadley drew a design on the margin of his note - book.

'So the man who called himself Pettis,' he mused, ' spoke to you through the door without seeing you? How did he know you two were there, do you think?'

Mangan frowned. 'He saw us through the window, I suppose. As you come up the front steps you can see straight into the front room through the nearest window. I always notice it myself. In fact, if I see anybody in the front room I usually lean across and tap on the window instead of ringing the bell.'

The superintendent was still drawing designs, meditatively. He seemed about to ask a question, but checked himself. Rosette regarded him with a sharp, unwinking gaze. Hadley merely said: 'Go on. You were waiting for ten o'clock -'

'And nothing happened,' Mangan insisted. 'But, a funny thing, every minute past ten o'clock I got more nervous instead of more relieved. I told you I didn't really expect the man would come, or that there would be any trouble. But I kept picturing that dark hall, and the queer suit of armour with the mask out there, and the more I thought of it the less I liked it ...'

'I know exactly what you mean,' said Rosette. She looked at him in a strange, rather startled manner. 'I was thinking the same thing. But I didn't want to talk about it in case you called me a fool.'

'Oh, I have these psychic fits too. That,' Mangan said bitterly, ' is why I get the sack so often, and why I shall probably get the sack for not phoning in this story to - night. News editor be d.a.m.ned. I'm no Judas." He shifted.' Anyway, it was nearly ten past ten when I felt I couldn't stand it any longer. I slammed down the cards and said to Rosette, "Look here, let's get a drink and turn on all the lights in the hall - or do something." I was going to ring for Annie when I remembered it was Sat.u.r.day and her night out ...

'Annie? That's the maid? Yes, I'd forgotten her. Well?'

'So I went over to open the door, and it was locked on the outside. It was like - this! You have some conspicuous object in your bedroom, like a picture or an ornament, that's so common you never fully notice it. Then one day you walk in and have a vague feeling that there's something wrong with the room. It irritates and disturbs you, because you can't imagine why. Then all of a sudden a gap jumps up, and you see with a shock that the object has been removed. Understand? I felt just like that. I knew something was wrong, I felt it ever since that fellow had sung out from the hall, but it never hit me with a smash until I found that door locked. Just as I began idiotically yanking at the k.n.o.b, we heard the shot.

'A firearm indoors makes a devil of a noise, and we heard it even up at the top of the house. Rosette screamed - '

'I did not!'

'Then she pointed at me and said what I'd been thinking, too. She said, "That wasn't Pettis at all. He's got in."'

'Can you fix the time of that?'

'Yes. It was just ten minutes past ten. Well, I tried to break the door down.' In spite of staring at that memory, a wry and mocking gleam of mirth twinkled in Mangan's eyes. It was as though he hated to speak, but could not help commenting, ' I say, have you ever noticed how easy it is to break down doors in the stories? Those stories are a carpenter's paradise. They're an endless trail of doors smashed down on the slightest pretext, even when somebody inside won't answer a casual question. But try it on one of these doors! ... That's about all. I banged my shoulder - bone against it for a while, and then I thought about getting out through the window and in again through the front door or the area door. I ran into you, and you know what happened.'

Hadley tapped the notebook with his pencil. 'Was it customary for the front door to be unlocked, Mr Mangan?'

'O Lord! I don't know! But it was the only thing I could think of. Anyhow, it was unlocked.'

'Yes, it was unlocked. Have you anything to add to that, Miss Grimaud?'

Her eyelids drooped. 'Nothing - that is, not exactly. Boyd has told you everything that happened just as it happened. But you people always want all kinds of queer things, don't you? Even if they don't seem to bear on the matter? This probably has nothing to do with the matter at all, but I'll tell you ... A little while before the door - bell rang, I was going over to get some cigarettes from a table between the windows. The radio was on, as Boyd says. But I heard from somewhere out in the street, or on the pavement in front of the door, a loud sound like - like a thud, as though a heavy object had fallen from a big height. It wasn't an ordinary street noise, you see. Like a man falling.'

Rampole felt himself stirring uneasily. Hadley asked: 'A thud, you say? H'm. Did you look out to see what it was?'

'Yes. But I couldn't see anything. Of course, I only pulled the blind back and peeped round the side of it, but I can swear the street was empt - ' She stopped in full flight. Her lips fell open a little and her eyes were suddenly fixed. 'Oh, my G.o.d!' she said.

'Yes, Miss Grimaud,' said Hadley without inflexion, ' the blinds were all down, as you say. I especially noticed that, because Mr Mangan got entangled with one when he jumped out. That was why I wondered how the visitor could have seen you through any window in that room. But possibly they weren't drawn down all the time?'

There was a silence, except for faint noises on the roof. Rampole glanced at Dr Fell, who was propped back against one of the unbreakable doors with his chin in his hand and his shovel - hat tilted over his eyes. Then Rampole looked at the impa.s.sive Hadley, and back to the girl.

'He thinks we're lying, Boyd,' said Rosette Grimaud coolly. 'I don't think we'd better say anything more.'

And then Hadley smiled. ' I don't think anything of the kind, Miss Grimaud. I'm going to tell you why, because you're the only person who can help us. I'm even going to tell you what did happen - Fell!'

'Eh?' boomed Dr Fell, looking up with a start.

'I want you to listen to this,' the superintendent pursued, grimly. ' A while ago you were having a lot of pleasure and mystification out of saying that you believed the stories - apparently incredible - told by Mills and Mrs Dumont; without giving any reasons why you believed them. I'll return the compliment. I'll say that I believe not only their story, but the story told by these two also. And, in explaining why, I'll also explain the impossible situation.'

This time Dr Fell did come out of his abstraction with a jerk. He puffed out his cheeks and peered at Hadley as though prepared to leap into battle.

'Not all of it, I admit,' pursued Hadley, 'but enough to narrow down the field of suspects to a few people, and to explain why there were no footprints in the snow.'

'Oh, that!' said Dr Fell contemptuously. He relaxed with a grunt. 'You know, for a second I hoped you had something. But that part is obvious.'

Hadley kept his temper with a violent effort. 'The man we want,' he went on, 'made no footprints on the pavement or up the steps because he never walked on the pavement or up the steps - after the snow had stopped. He was in the house all the time. He had been in the house for some time. He was either (a) an inmate; or (b) more probably somebody who had concealed himself there, using a key to the front door earlier in the evening. This would explain all the inconsistencies in everybody's story. At the proper time he put on his fancy rig, stepped outside the front door on the swept door - step, and rang the door - bell. It explains how he knew Miss Grimaud and Mr Mangan were in the front room when the blinds were drawn - he had seen them go in. It explains how, when the door was slammed in his face and he was told to wait outside, he could simply walk in - he had a key.'

Dr Fell was slowly shaking his head and rumbling to himself. He folded his arms argumentatively.

'H'm, yes. But why should even a slightly cracked person indulge in all that elaborate hocus - pocus? If he lived in the house, the argument isn't bad: he wanted to make the visitor seem an outsider. But if he really came from outside, why take the dangerous risk of hanging about inside long before he was ready to act? Why not march straight up at the right time?'

'First,' said the methodical Hadley, checking it off on his fingers, 'he had to know where people were, so as to have no interference. Second, and more important, he wanted to put the finishing touches on his vanishing - trick by having no footprints whatever, anywhere, in the snow. The vanishing - trick would be everything to the crazy mind of - brother Henri, let's say. So he got in while it was snowing heavily, in id waited until it had stopped.'

'Who,' Rosette asked in a sharp voice, 'is brother Henri?'

'He's a name, my dear,' Dr Fell returned affably. 'I told you that you didn't know him ... Now, Hadley, here's where I enter a mild, firm objection to this whole rummy affair. We've talked glibly about snow starting and stopping, as though you could regulate it like a tap. But I want to know how in blazes a man can tell WHEN snow is going to start or stop? That is a man seldom says to himself, "Aha! On Sat.u.r.day night I will commit a crime. On that night, I think, it will commence to snow at exactly 5 p.m., and leave off at exactly 9.30 p.m. This will afford me ample time to get into the house, and be prepared with my trick when the snowfall ends." Tut, tut! Your explanation is rather more staggering than your problem. It's much easier to believe that a man walked on snow without leaving a footprint than to believe he knew precisely when he would have it to walk on.'

The superintendent was irritable. 'I am trying,' he said, ' to get to the main point of all this. But if you must fight about that - Don't you see it explains away the last problem?'

'What problem?'

'Our friend Mangan here says that the visitor threatened to pay his visit at ten o'clock. Mrs Dumont and Mills say nine - thirty. Wait!' He checked Mangan's outburst. 'Was A lying or B? First, what sane reason could either have for lying afterwards about the time he threatened to come? Second, if A says ten o'clock and B says nine - thirty, then, innocent or guilty, one of the two should have learned beforehand the time at which the visitor really would arrive. And which was right about the time he did arrive?'

'Neither,' said Mangan, staring, 'It was between 'em. At nine - forty - five.'

'Yes. That's a sign that neither lied. It's a sign that the visitor's threat to Grimaud was not definite; it was "nine - thirty or ten o'clock or thereabouts". And Grimaud who was trying pretty desperately to act as though the threat hadn't scared him, nevertheless took very good care to mention both times in order to make sure everybody was there. My wife does the same thing with invitations to bridge parties ... Well, but why couldn't brother Henri be definite? Because, as Fell says, he couldn't turn off the snow like a tap. He could risk a long gamble on there being snow to - night, as there's been for several nights; but he had to wait until it stopped even if he waited until midnight. He didn't have to wait so long. It stopped at half - past nine. And then he acted exactly as such a lunatic would - he waited fifteen minutes so that there could be no argument afterwards, and rang the bell.'

Dr Fell opened his mouth to speak, looked shrewdly at the intent faces of Rosette and Mangan, and stopped.

'Now, then!' said Hadley, squaring his shoulders. ' I've shown you two that I believe everything you say, because I want your help on the most important thing this tells us ... The man we want is no casual acquaintance. He knows this house inside out - the rooms, the routine, the habits of the occupants. He knows your phrases and nicknames. He knows how this Mr Pettis is accustomed to address not only Dr Grimaud, but you; hence he's no casual business friend of the professor whom you haven't seen. So I want to know all about everybody who's a frequent enough visitor to this house, everybody who is close enough to Dr Grimaud to answer the description.'

She moved uneasily, startled. 'You think - somebody like that... Oh, it's impossible! No, no, no!' (It was a queer echo of her mother's voice.) 'Not anybody like that, anyhow!'

'Why do you say that?' Hadley asked sharply. ' Do you know who shot your father?'

The sudden crack of the words made her jump. 'No, of course not!'

'Or have any suspicion?'

'No. Except,' her teeth gleamed, 'I don't see why you should keep looking outside the house. That was a very nice little lesson in deduction you gave, and thanks awfully. But if the person had come from inside the house, and acted as you said, then it would really be reasonable, wouldn't it? It would apply much better.'

'To whom?'

'Let's see! Well - that's your business, isn't it?' (He had somehow stirred a sleek tiger cat, and she was enjoying it.) 'Of course you haven't met the whole household. You haven't met Annie - or Mr Drayman, come to think of it. But your other idea is utterly ridiculous. In the first place, my father has very few friends. Outside of the people in this house, there are only two who fit the qualifications, and neither of them could possibly be the man you want. They couldn't be in the mere matter of their physical characteristics. One is Anthony Pettis himself; he's no taller than I am, and I'm no Amazon. The other is Jerome Burnaby, the artist who did that queer picture. He has a deformity; a slight one, but it couldn't be disguised and anybody could spot it a mile away. Aunt Ernestine or Stuart would have known him instantly.'

'All the same, what do you know about them?'

She lifted her shoulders. 'Both are middle - aged, well - to - do, and potter after their hobbies. Pettis is bald - headed and fastidious ... I don't mean he's old - womanish; he's what the men call a good fellow, and he's clever as sin. Bah! Why won't they do something with themselves!' She clenched her hands. Then she glanced up at Mangan and a slow, calculating, drowsily pleasant expression came into her look. 'Burnaby - yes, Jerome has done something with himself, in a way. He's fairly well known as an artist, though he'd rather be known as a criminologist. He's big and bluff; he likes to talk about crime and brag about his athletic prowess of old. Jerome is attractive in his way. He's very fond of me, and Boyd is horribly jealous.' Her smile widened.

'I don't like the fellow,' said Mangan, quietly. 'In fact, I hate him like poison - and we both know it. But at least Rosette's right about one thing. He'd never do a thing like that.'

Hadley scribbled again. 'What is this deformity of his?'

'A club - foot. You can see how he couldn't possibly conceal it.'

'Thank you. For the moment,' said Hadley, shutting up his note - book, 'that will be all. I should suggest that you go along to the nursing - home. Unless - er - any questions, Fell?'

The doctor stumped forward. He towered over the girl, peering down at her with his head a little on one side.

'Just one last question,' he said, brushing aside the black ribbon of his eye - gla.s.ses as he would a fly. ' Harrumph! Ha! Now! Miss Grimaud, why are you so certain that the guilty person is this Mr Drayman?'

CHAPTER 8.

THE BULLET.

HE never received any answer to that question, although he received some illumination. It was all over before Rampole realised what had happened. Since the doctor had spoken with the greatest casualness, the name 'Drayman' had made no impression on Rampole and he was not even looking at Rosette. Uneasily, he had been wondering for some time what had happened to change the gusty, garrulous, beaming Mangan he used to know into this shuffling figure who backed and deprecated and talked like a fool. In the past Mangan had never talked like a fool, even when he talked like an idiot. But now - 'You devil!' cried Rosette Grimaud.

It was like a screech of chalk on a blackboard. Rampole whirled round to see high cheek - bones gone still higher as her mouth widened, and a blaze that seemed to take the colour from her eyes. It was only a glimpse; she had flung herself past Dr Fell, the mink coat flying, and out into the hall, with Mangan after her. The door slammed. Mangan reappeared for a moment, said to them, 'Er - sorry!' and quickly closed the door once more. He looked almost grotesque in the doorway, his back bent and his head lowered, so that it seemed all wrinkled forehead and nervous dark eyes shining intensely. His hands were extended, with palms turned down, as though he were trying to quiet an audience. 'Er - sorry!' he said, and closed the door.

Dr Fell remained blinking at it.

'She's her father's daughter, Hadley,' he wheezed, and shook his head slowly. 'Harrumph, yes. She goes just so far under hard emotional pressure; very quiet, powder packed into a cartridge; then some little thing jars the hair trigger, and - h'm. I'm afraid she's morbid in the real sense, but maybe she thinks she has reason to be. I wonder how much she knows?'

'Oh, well, she's a foreigner. But that's not the point. It seems to me,' said Hadley, with some asperity, ' that you're always making a wild shot like a trick rifleman and knocking the cigarette out of somebody's mouth. What was that business about Drayman, anyhow?'

Dr Fell seemed bothered. 'In a minute, in a minute ... What did you think of her, Hadley? And Mangan?' He turned to Rampole.' My ideas are a little mixed. I'd got the impression, from what you said, that Mangan was a wild Irishman of the type I know and like.'

'He was,' said Rampole.' Understand?'

'As to what I think of her,' Hadley said, 'I think she could sit there as cool as you please, a.n.a.lysing her father's life (she's got a d.a.m.ned good head on her, by the way); and yet at this moment I'll bet she's in tears and hysterics rushing across there, because she didn't show him enough consideration. I think she's fundamentally sound. But she's got the Old Nick in her, Fell. She wants a master in both senses. She and Mangan will never hit it off until he has sense enough to punch her head or take her own advice at the London University debate.'

'Ever since you have become superintendent of the C.I.D.,' declared Dr Fell, squinting at him,' I have detected in you a certain raffish air which pains and surprises me. Listen, you old satyr. Did you honestly believe all that rubbish you talked, about the murderer sneaking into this house to wait until the snow - storm had stopped?'

Hadley permitted himself a broad grin. ' It's as good an explanation as any,' he said, 'until I can think of a better. And it keeps their minds occupied. Always keep witnesses' minds occupied. At least I believe their story ... We're going to find something in the way of footprints on that roof, don't you worry. But we'll talk about that later. What about Drayman?'

'To begin with, I had stuck in my mind an odd remark made by Madame Dumont. It was so odd that it jumped out of the sentence. Not a calculated remark; she cried it out at the time she was most hysterical, when she could not understand why even murderers acted out so silly a charade. She said (if you wish to kill somebody), "You do not put on a painted mask, like old Drayman with the children on Guy Fawkes night." I filed away the suggestion of this Guy Fawkes spectre, wondering what it meant. Then, all unintentionally, I phrased a question about Pettis - when speaking to Rosette - with the words, "dressed up like a Fifth of November Guy?" Did you notice her expression, Hadley? Just my suggestion that the visitor was dressed like that gave her the hint, but it startled her as much as it pleased her. She didn't say anything; she was thinking. She hated the person she was thinking of. What person?'

Hadley stared across the room.' Yes, I remember. I could see she was hinting at somebody she suspected or wanted us to suspect; that was why I asked her flat out. She practically made me see it was somebody in this house. But to tell you the truth,' - he rubbed his hand across his forehead - ' this is such a rum crowd that for a second I thought she was hinting at her own mother.'

'Not by the way she dragged in Drayman. "You haven't met Annie - or Mr Drayman, come to think of it." The important news was in the postscript...' Dr Fell stumped round the typewriter desk, peering malevolently at the gla.s.s of milk. 'We must rout him out. He interests me. Who is this Drayman, this old friend and hanger - on of Grimaud, who takes sleeping draughts and wears Fifth of November masks? What's his place in the household; what's he doing here, anyway?'

'You mean - blackmail?'

'Rubbish, my boy. Did you ever hear of a schoolmaster being a blackmailer? No, no. They're much too worried about what people might find out about them. The academic profession has its faults, as I know for my sins; but it doesn't produce blackmailers ... No, it was probably only a kindly impulse of Grimaud to take him in. but -'

He paused as a rush of cold air blew his cloak. A door across the room, evidently communicating with a staircase to the attic and the roof, opened and shut. Mills popped in. His mouth was bluish and a large wool m.u.f.fler was wound round his neck; but he looked warm with satisfaction. After refreshing himself with a pull at - the gla.s.s of milk (impa.s.sively, with head thrown back in a way which somehow suggested a sword - swallower), he put out his hands to the fire.

He chattered: 'I have been watching your detective, gentlemen, from a point of vantage at the top of the trapdoor. He has caused a few landslides, but - Excuse me! Didn't you have a commission of some description for me to execute? Ah, yes. I am anxious to lend a.s.sistance, but I fear I forgot -'

'Wake up Mr Drayman,' the superintendent said, 'if you have to slosh him with water. And - Hullo! Pettis! If Mr Pettis is still here, tell him I want to see him. What did Sergeant Betts discover up there?'

Betts answered for himself. He looked as though he had taken a header in a ski - jump; he breathed hard, stamped and slapped the snow from his clothes as he shook his way towards the fire.

'Sir,' he announced, 'you can take my word for it that not even a bird's lit on that roof anywhere. There's no mark of any kind in any place. I've covered every foot of it.' He stripped off his sodden gloves. 'I had myself tied on a rope to each of the chimneys, so I could get down and crawl straight along the gutters. Nothing round the edges, nothing round the chimneys, nothing anywhere. If anybody got up on that roof to - night, he must have been lighter than air. Now I'll go down and have a look at the back garden...'

'But -!' cried Hadley.

'Quite so,' said Dr Fell. 'Look here, we'd better go down and see what your bloodhounds are doing in the other room. If the good Preston - '

Sergeant Preston, fuming a little, pulled open the door to the hall as though he had been summoned. He looked at Betts and back to Hadley.

'It's taken me a little time, sir,' he reported, 'because we had to pull out all those bookcases and shove 'em back again. The answer is nothing! No secret entrance of any kind. Chimney's solid and no funny business about it; flue's only about two or three inches wide, and goes up on an angle at that... Is that all, sir? The boys have finished.'

'Fingerprints?'

'Plenty of prints, except - You raised and lowered that window yourself, didn't you, sir? With your fingers on the gla.s.s up near the top of the frame? I recognized your prints.'

'I am generally careful about things like that,' snapped Hadley. 'Well?'

'Nothing else on the gla.s.s. And all the woodwork of that window, frame and sill, is a high gloss varnish that'd take a glove - smudge as clear as a print. There's nothing, not even a smudge. If anybody went out there, he must have stood back and dived out head first without touching anything.'

'That's enough, thanks,' said Hadley. 'Wait downstairs. Get after that back garden, Betts ... No, wait, Mr Mills. Preston will fetch Mr Pettis, if he's still there. I should like to speak to you.'

'It would seem,' said Mills, rather shrilly, when the other two had gone, 'that we return to doubts about my own story. I a.s.sure you I am telling the truth. Here is where I sat. See for yourself.'

Hadley opened the door. Ahead of them the high, sombre hallway ran thirty feet to the door opposite - a door brilliantly illuminated by the glow from under the archway.

'I don't suppose there's any possibility of a mistake?' muttered the superintendent. 'That he really didn't go in, or something like that? A lot of funny business might go on in a shuffle at the doorway; I've heard of its being done. I don't suppose the woman was up to any funny business, dressing up in a mask herself, or - No, you saw them together, and anyway - h.e.l.l!'

'There was absolutely none of what you describe as funny business,' said Mills. Even in his perspiring earnestness he handled the last two words with distaste. 'I saw all three of them clearly and wide apart. Madame Dumont was in front of the door, yes; but towards the right. The tall man was towards the left, and Dr Grimaud separating them. The tall man really did go in; he closed the door behind him; and he did not come out. It is not as though the occurrence took place in half - light. There was no possibility of ever mistaking that man's gigantic stature.'

'I don't see how we can doubt it, Hadley,' said Dr Fell, after a pause. 'We've got to eliminate the door also.' He wheeled round. ' What do you know about this man Drayman?'

Mills's eyes narrowed. His singsong voice had a guarded quality.

'It is true, sir, that he offers a subject for intelligent curiosity. Hurrum! But I know very little. He has been here some years, I am informed; in any event, before I arrived. He was forced to give up his academic work because he had gone almost blind. He is still almost blind, in spite of treatment, although you would not deduce this from the - er - aspect of his eyes. He appealed to Dr Grimaud for help.'

'Had he some sort of claim on Dr Grimaud?'