'That is quite possible,' said Hannasyde. 'Some little time elapsed between your seeing your aunt at breakfast and the butler's meeting her in the hall. I appreciate your feelings in the matter, Mr Matthews, but you are doing no good by this sort of interruption.'

'There's one thing you seem to be leaving out of account,' said Guy, disregarding this warning. 'Both my sister and I can certify that my aunt complained of feeling ill at breakfast, before ever she had seen my mother. If you imagine there was nicotine in the medicine my mother gave her, I would remind you that it was given at least an hour after she began to feel ill-and, since you set so much store by what Beecher says-after he had met her in the hall, and been struck by her appearance.'

'I am quite aware of that, Mr Matthews.'

'It is utterly absurd,' said Mrs Matthews, pressing her handkerchief to her lips, 'but the Superintendent seems to think that I could have put that dreadful poison into your aunt's early-morning teapot.' She gave a wan smile, and added: 'If it were not such a painful thought, so wounding to one's feeling, I could laugh at it! I haven't the least idea what was done with the early tea-trays, and I didn't wake until the housemaid came into my room, so how I could have tampered with your aunt's teapot, I entirely fail to see.'

'You say that you only awoke when the maid came into your room, Mrs Matthews, but she states that you were already awake when she went in. Are you quite sure that you are telling me the truth?'

'I suppose,' said Mrs Matthews tragically, 'that you are at liberty to insult me as much as you choose. It only remains for you to arrest me. Indeed, I am astonished that you haven't done so already.'

Hannasyde did not answer immediately, and Guy, who at the mention of the early tea had shot one swift, horrified look at his sister, now removed his hand from the back of his mother's chair, and said jerkily: 'n.o.body's going to arrest you, mother, I can a.s.sure you. You're very clever, Superintendent, but it was I who poisoned my aunt, not my mother.'

'Guy, you fool!' Stella cried.

He paid no attention to her, but looked squarely at Hannasyde. Mrs Matthews said tensely: 'That's not true! Don't listen to him! I know it's not true!'

Hannasyde met Guy's bright, defiant eyes with an enigmatical look in his own. 'How did you poison your aunt, Mr Matthews?'

'In her tea,' replied Guy. 'The tea she had at breakfast. I was down first. I knew my sister always has coffee. When I told you I drank tea that day, I lied. I didn't. I drank coffee.'

'No, Guy, no!' said his mother. 'You don't know what you're saying! Superintendent, my son is only trying to shield me! There's not a word of truth in what he says! You can see for yourself -'

'Did you also poison your uncle, Mr Matthews?' inquired Hannasyde.

'Yes, in the whiskey-and-soda,' replied Guy recklessly.

'Stop being theatrical!' Stella said angrily. 'What good do you think you're doing, making dramatic gestures? You did not drink coffee that morning, or any other morning! You don't like coffee! You're behaving like someone in a penny novelette!'

Guy paid no heed to this, but continued to address the Superintendent. 'Well, have you got a warrant for my arrest?' he demanded.

'No, I'm afraid I haven't,' replied Hannasyde.

'Then you'd better go and apply for one!' said Guy.

'When I am satisfied that I have sufficient grounds for doing so, I will,' promised Hannasyde.

'I don't know what more you want!' said Guy, in a somewhat flattened voice.

Sergeant Hemingway came into the room at that moment, and handed his superior a sealed envelope.

'Excuse me, please,' Hannasyde said formally, and tore open the envelope, and spread open the single sheet it contained. He ran his eye down the typewritten lines, and then looked up, and at Guy, who said at once: 'You're wasting your time trying to badger my mother. I've told you what happened. Now get on with it, and arrest me!'

'I am sorry, Mr Matthews, but you have not shown me sufficient grounds for applying for a warrant for your arrest. You have stated that you put the poison in your aunt's tea, but Miss Matthews did not swallow the nicotine which killed her.'

These words produced a sudden, surprised silence. Guy broke it. 'What do you mean, she didn't swallow it? She must have swallowed it!'

'Yes, I thought you didn't know quite as much about it as you pretended, Mr Matthews,' said Hannasyde. 'The nicotine did not pa.s.s through the stomach. It was absorbed through the tissues of the mouth.' He held up the paper in his hand. 'This is the a.n.a.lyst's report, which I've been waiting for. The medium through which your aunt was poisoned was a tube of toothpaste.'

'A-tube-of-toothpaste?' Guy repeated, blankly, and then was silent.

Hannasyde folded the report again, and put it away in his pocketbook. The deliberation of his movements seemed to fascinate Stella; her eyes followed them in a kind of numb bewilderment while a jumble of thoughts chased one another through her brain. These found expression presently in one sentence, blurted out unwarily. 'Then anyone might have done it!'

'I don't think so, Miss Matthews.'

Mrs Matthews said with something of her usual smoothness: 'Stella darling, just sit down and be quiet. You don't know anything about this, my dear child, and you must not keep on interrupting.' She turned towards Hannasyde, and said graciously: 'You see now how absurd your suspicions were, Superintendent. We won't say any more about it, however. Naturally I understand that your duty compels you to suspect everybody. But this is most amazing news! A tube of toothpaste! You mean, I suppose, that the poison was injected into it. A hypodermic syringe, no doubt. I don't think that anyone in this house owns such a thing. It is a very, very terrible thought that my poor sister-in-law should have -'

Guy made an impatient gesture, as though to silence her. 'How was it done?' he asked. 'Are you at liberty to tell us that?'

'Certainly,' said Hannasyde. 'The poison was in all probability injected, as your mother seems to have realised, by means of a hypodermic syringe, inserted into the bottom end of the tube, and driven up a little way through the paste. The paste at the bottom of the tube is untainted, and it is obvious that the paste at the top end must also have been free from poison.'

Guy said softly: 'By Jove, that's clever! It might have been done at any time, then. Aunt Harriet has been working her way down the tube for days, till at last she reached the poison! Gosh!'

'It's awful!' Stella said. 'It's devilish!'

'One can only be thankful poor Harriet knew nothing about it,' remarked Mrs Matthews in a saintly voice.

'For G.o.d's sake don't talk as though she were a sheep being driven to the slaughter-house!' exclaimed Stella, quite pale with disgust.

'Stella dear, you forget yourself,' said Mrs Matthews repressively. She transferred her attention to the Superintendent. 'One is terribly shocked, of course, but what my son says is right. This appalling thing may have been done at any time.'

'But not, Mrs Matthews, by any person,' replied Hannasyde.

She spread out her hands. 'Anyone who was familiar with this house could have found the opportunity to do it, Superintendent.'

'Possibly,' agreed Hannasyde. 'But few people can have had any motive for killing Miss Matthews.'

Guy muttered: 'O G.o.d, we're just where we were before!'

'Ah, Superintendent,' said Mrs Matthews, sadly shaking her head. 'What, after all, do we know of each other's lives? Even I who was so close to my poor sister-in-law would hesitate to say that she had no enemies of whom I knew nothing. She was a strange, eccentric woman! I have sometimes wondered whether there might not have been something in the past to account for many of her oddities. So often an apparently warped nature -'

'If you, who were so close to her, do not know of anything sinister in her past, I think we may a.s.sume that there was nothing,' interrupted Hannasyde, with an inflection of contempt in his voice. 'The discovery of the medium through which the poison was administered has not enlarged the field of suspects, as a moment's reflection will, I think, show you.'

Stella grasped a chairback, and said desperately: 'But not one of us three had a motive for killing Aunt Harriet! Not a real motive! This is like a nightmare! Things don't happen like this! Leave me alone, mother: I won't be quiet!' She shook off her mother's hand, laid warningly on her arm, and said, trembling: 'I don't pretend to know who did it. Perhaps she knew something that-that made her dangerous. Supposing it were something about that man you're looking for-the one who disappeared?'

'Well?' said Hannasyde.

'Oh, I don't know!' she said wretchedly. 'How can I know? But why don't you try and find out? My cousin told us about that man, and how you believe he had something to do with my uncle's death. Perhaps Aunt knew something about him. After all, we haven't always lived here; we don't know what may have happened in the past. My mother is quite right! You didn't know my uncle, or how Aunt Harriet hated him. Perhaps she was in a plot to murder him, and then-oh, I know this sounds far-fetched, but it isn't as far-fetched as thinking that my mother could murder aunt in that awful, coldblooded way just to get this house to herself!' Her voice broke, but she controlled it and added: 'I had as strong a motive as my mother!'

'So had I,' said Guy. 'A much stronger one than either of yours, too.'

'No, that isn't true,' Stella answered. 'You were the only one who really liked Aunt Harriet! You always stood up for her when Mummy and I ran her down. And she didn't interfere with you. She was awfully fond of you!'

'So much so that she left me her money. Don't forget that bit,' interrupted Guy.

'You didn't want her money! Superintendent, it's all rubbish about my aunt's money! She only had quite a little, and now that Uncle Gregory's dead my brother can do what he likes with his own capital!' She stopped short, aware of the implication of her own words, and grew whiter than ever. 'No. I don't mean-I didn't -'

The door opened. 'What a charming reunion!' remarked a mellifluous voice. 'I'm so glad. I'm not too late to join in. I should not have liked to have missed the dear Superintendent.'

'Oh, Randall!' gasped Stella, and released the chairback, and fled towards him, and clung to his arm.

He looked down at her with a curious lift to his brows. Guy, staring in astonishment at his sister's behaviour, saw a gleam in the blue eyes, hard to interpret.

Randall laid his hand on Stella's, but only to remove it from his sleeve. 'My precious, you really must have some regard for my clothes,' he said with gentle reproach. 'Much as I love you, I cannot permit you to maul this particular coat.' He drew her hand through his arm, and walked forward with her, his fingers still lightly clasping hers. 'Now what has been happening to upset my little cousin Stella?' he inquired of the room at large. 'Have you been accusing her of murdering my late aunt, Superintendent?'

'No,' said Hannasyde, 'I have not.'

'You had better tell me all about it,' said Randall amiably. 'I can see that you are all of you-ah, pregnant with news.'

'Really, Randall!' protested Mrs Matthews.

'They've found out what the poison was put into,' said Guy.

'Have they indeed? Well, that's very nice,' said Randall. 'And what was it put into?'

'A tube of toothpaste,' answered Guy.

Randall had led Stella to a chair, and seemed to be more interested in seeing her comfortably settled into it than in Guy's disclosure. It was just a moment before he spoke, and then he merely said: 'Really? Some ingenious brain at work, apparently.'

'That's exactly what I was thinking,' said Guy. 'd.a.m.ned ingenious!'

Randall turned away from Stella, and regarded Guy with veiled amus.e.m.e.nt. 'Well, don't stop,' he said encouragingly. 'What else were you thinking?'

'I don't know that I was thinking of anything else,' said Guy slowly.

'Physical disability, or cousinly forbearance?' inquired Randall, taking a cigarette out of his case and setting it between his lips.

'Neither. But Stella was saying just as you came in that perhaps Aunt Harriet was mixed up in some way with that missing fellow you told us about. Perhaps she knew too much, and that was why she was poisoned.'

Randall lit his cigarette. 'On no account miss tomorrow's instalment of this thrilling story,' he murmured. 'What do you call it, sweetheart? The Hand of Death? I can see that the Superintendent is positively spellbound. And so Aunt Harriet carried her secret with her to the grave! Well, well!'

'It isn't funny!' snapped Guy.

'Not in the least; it's maudlin,' said Randall crushingly.

'I don't see why there shouldn't be something in it. After all -'

Randall moaned, and covered his eyes with his hand. 'My poor little cousin, have you no sense of the ludicrous?'

'Randall, there might have been something we didn't know about,' Stella said in a low voice.

He glanced down at her. 'In Aunt Harriet's life? Pull yourself together, darling.'

It was at this moment that Mrs Lupton sailed into the room, swept a look round, and said in a portentous voice: 'I thought as much!'

'That's very interesting,' said Randall, turning towards her immediately. 'As much as what?'

'I have not come here to bandy words with you, Randall, but to find out what has been going on in this house. From the presence of these two gentlemen I deduce that my unfortunate sister, incredible as it may seem, was indeed poisoned. I demand to be told exactly what has happened!'

'Well, at the moment,' said Randall, 'we are discussing an entrancing theory that your unfortunate sister was murdered because she was in possession of some hideous secret.'

Mrs Lupton cast a withering glance upon him. 'Harriet was never able to keep a secret in her life,' she said. 'I do not know who was responsible for this piece of nonsense, but I may say that I strongly object to it.' She glared at Hannasyde. 'Have you found out how my sister was poisoned, or are you going to tell me that you are still in the dark?'

'Your sister was poisoned through the medium of a tube of toothpaste,' answered Hannasyde, who had drawn a little way back from the group, and had been silently watching and listening.

Mrs Lupton repeated: 'A tube of toothpaste? I never heard of such a thing!'

'What a valuable contribution to our symposium!' remarked Randall.

'Who did it?' demanded Mrs Lupton sternly. 'That is what I wish to know! That is what has got to be found out! Good heavens, do you realise that not one but two murders have been committed, and not one thing has been done about it?'

'My dear aunt, "them," not "it," ' corrected Randall in a pained voice.

'I am forced to look the facts in the face,' continued Mrs Lupton, disregarding this interruption, 'and disagreeable though it may be, I am not one to shirk the truth. My brother and my sister have been murdered in cold blood, and I know of only one person who could have done it, or who had a motive for doing it!'

Mrs Matthews rose to her feet. 'If you mean me, Gertrude, pray do not hesitate to say so!' she begged. 'I am becoming quite accustomed to having the most heartless and wicked accusations made against me! But I should very much like to know how I am supposed to have got hold of any nicotine!'

'We all know how morbidly interested you are in anything to do with illness or medicine,' returned Mrs Lupton. 'No doubt you could have found out, had you wanted to, where to obtain nicotine.'

Stella sat up suddenly. 'You don't buy nicotine,' she said. 'You extract it from tobacco. Deryk Fielding told me so. Mother wouldn't have known how to do that.'

'If it comes to that,' said Guy, 'who would know, except Fielding himself?' He looked quickly up, and across the room at his cousin, his eyes narrow all at once. 'Or-you, Randall!'

Randall was unperturbed by this attack. He merely tipped the ash off the end of his cigarette, and said: 'Somehow I thought it wouldn't be long before I was identified with the mysterious killer of Stella's little bedtime story.'

Mrs Lupton fixed him with a cold, appraising stare. 'Yes,' she said slowly, 'that is perfectly true, though what reason you could have had for poisoning your Aunt Harriet I fail to see. But perhaps the Superintendent is not aware that you were training to be a doctor when your father died?'

'Yes, Mrs Lupton, I am aware of that,' Hannasyde replied.

'I do not say that it has necessarily any bearing on this case,' said Mrs Lupton fairly. 'But the fact remains that you have a certain medical knowledge. You had also the strongest motive of anyone for murdering your uncle Gregory.'

Stella said, grasping the arms of her chair: 'No! No, he hasn't. He doesn't want uncle's money. He told me himself he was going to get rid of it.'

An astonished silence greeted her words. Hannasyde, closely watching Randall, saw a flicker of annoyance in his face, and caught the gleam of warning in the look he flashed at Stella.

Guy broke the silence. 'You-don't-want-uncle's-money?' he repeated. 'What rot! I never heard such a tale!'

He burst out laughing, but Hannasyde's voice cut through his laughter. 'That is very interesting, Mr Matthews. May I know why you don't want your inheritance?'

'It's as plain as a pikestaff!' said Guy scornfully. 'He said it so that no one should suspect him of having poisoned uncle.'

'Thank you,' said Hannasyde. 'But I spoke to your cousin, Mr Matthews, not to you.'

Randall was frowningly regarding the tip of his cigarette. He raised his eyes when Hannasyde spoke, and answered pensively: 'Well, do you know, I like to shock my family now and then, my dear Superintendent.'

'You did not by any chance mean what you said to Miss Stella Matthews?'

Randall's lip curled sardonically. 'Is it possible that anyone could wish to be rid of a large fortune?' he said mockingly. 'The answer is to be read in my relatives' expressive countenances. They are more profoundly shocked than if it had been proved to them that I murdered my uncle and my aunt.' He moved towards the table and put his cigarette out in the ashtray that stood on it. 'However, what I mean to do with my inheritance is not in the least relevant to the matter on hand. You mustn't think that I don't know how much you would like my deplorable relatives to continue their artless and revealing discussions, but-I think not, Superintendent: I think not! Let us stick to my aunt's death, shall we? You do not really believe that I had any hand in that-ah, setting aside my cousin Stella's engaging theory, of course. You suspect, and so does my dear Aunt Gertrude, that my clever Aunt Zo is the guilty party. I don't blame you in the least. I will even go so far as to say that I don't blame my dear Aunt Gertrude either. With her own fair hands my clever aunt built up the case against herself, and I must say it does her credit. It worries you, doesn't it, Superintendent? My Aunt Harriet's death has upset a cherished theory of your own; in fact, it is quite out of order.'