"Possibly. You may know more about him than I."

"Even then, we have not traveled far as yet."

Fowler was puzzled, and did not hesitate to show it. He believed, not without reasonable cause, that this young man was concealing some element in the situation which might prove helpful in the quest for the murderer.

He resolved to strike off along a new track.

"I am informed," he went on, speaking with a deliberateness meant to be impressive, "that you did entertain another lady as a visitor last night."

Grant allowed his glance to dwell on Robinson for an instant. Hitherto he had ignored the man. Now he surveyed him as if he were a viper.

"It will be a peculiarly offensive thing if the personality of a helpless and unoffending girl is brought into this inquiry," he cried. "'Brought in' is too mild--I ought to say 'dragged in.' As it happens, astronomy is one of my hobbies. Last evening, as the outcome of a chat on the subject, Doris Martin, daughter of the local postmaster, came here to view Sirius through an astronomical telescope. There is the instrument," and he pointed through P.C. Robinson to a telescope on a tripod in a corner of the room. The gesture was eloquent. The burly policeman might have been a sheet of gla.s.s. "As you see, it is a solid article, not easily lifted about. It weighs nearly a hundred-weight."

"Why is it so heavy?"

The superintendent had a knack of putting seemingly irrelevant questions.

Robinson had been disconcerted by it earlier in the day, but Grant seemed to treat the interruption as a sensible one.

"For observation purposes an astronomical telescope is not of much use unless the movement of the earth is counteracted," he said. "Usually, the dome of an observatory swings on a specially contrived axis, but that is a very expensive structure, so my telescope is governed by a clockwork attachment and moves on its own axis."

Mr. Fowler nodded. He was really a very well informed man for a country police-officer; he understood clearly.

"Miss Martin came here about a quarter to ten," continued Grant, "and left within three-quarters of an hour. She did not enter the house. She was watching Sirius while I explained the methods whereby the distance of any star from the earth is computed and its chemical a.n.a.lysis determined--"

"Most instructive, I'm sure," put in the superintendent.

He smiled genially, so genially that Grant dismissed the notion that the other might, in vulgar parlance, be pulling his leg.

"Well, that is the be-all and end-all of Miss Martin's presence. It would be cruel, and unfair, if a girl of her age were forced into a distasteful prominence in connection with a crime with which she is no more related than with Sirius itself."

The older man shook his head in regretful dissent.

"That is just where you and I differ," he said. "That very point leads us back to your past friendship with the dead woman."

"Why?"

"Surely you see, Mr. Grant, that Miss Melhuish might be, probably was, watching your star-gazing, especially as your pupil chanced to be, shall I say, a remarkably attractive young lady ... No, no," for Grant's anger was unmistakable--"It does no good to blaze out in protest. An unhappy combination of circ.u.mstances must be faced candidly. Here are you and a pretty girl together in a garden at a rather late hour, and a woman whom you once wanted to marry spying on you, in all likelihood. I've met a few coroner's juries in my time, and not one of them but would deem the coincidence strange, to put it mildly."

"What in Heaven's name are you driving at?"

"You must not impute motives, sir. I am seeking them, not supplying them."

"But what am I to say?"

"Perhaps you will now tell me just how Miss Melhuish and you parted."

The fencers were coming to close quarters. Even P. C. Robinson had to admit that his "boss" had cornered the suspect rather cleverly.

Grant realized that there was no room for squeamishness in this affair.

If he did not speak out now, his motives might be woefully misunderstood.

"We parted in wrath and tears," he said sadly. "Miss Melhuish could not, or did not, appreciate my scruples. She professed to be in love with me.

She even went so far as to threaten suicide. I--hardly believed in her sincerity, but thought it advisable to temporize, and asked for a few days' delay before we came to a final decision. We met again, as I have said, and discussed matters in calmer mood. Ultimately, she professed agreement with my point of view, and we parted, ostensibly to remain good friends, but really to separate for ever."

"Thank you. That's better. What _was_ your point of view, Mr. Grant?"

"Surely I have made it clear. I could not regard my wife as purchasable.

The proposed compact was, I believe, illegal. But that consideration did not sway me. I had been dreaming, and thought I was roaming in an enchanted garden. I awoke, and found myself in a mora.s.s."

The superintendent nodded again. Singularly enough, Grant's somewhat high-flown simile appeared to satisfy his craving for light.

"Do you mind telling me--is there another woman?" he demanded, with one of those rapid transitions of topic in which he excelled.

"No," said Grant.

"You see what I am aiming at. Let us suppose that Miss Melhuish never, in her own mind, abandoned the hope that some day the tangle would straighten itself. Women are const.i.tuted that way. If her husband is now dead, and she became free, she might wish to renew the old ties, but, being proud, would want to ascertain first whether or not any other woman had come into your life."

"I follow perfectly," said Grant, with some bitterness. "She would be consumed with jealousy because my companion in the garden last night happened to be a charming girl of nineteen."

"It is possible."

"So she went off and got someone to kill her, and tie her body with a rope, and arrange a dramatic setting whereby it would be patent to the meanest intelligence that I was the criminal?"

Mr. Fowler smiled, and looked fixedly at P.C. Robinson.

"No, no," he said, quite good-humoredly. "That would be carrying realism to extremes. Still, I am convinced, Mr. Grant, that this mystery is bound up in some way with your romance of three years ago. At present, I admit, I am working in the dark."

He rose. Apparently, the interview was at an end. But, while pocketing his note-book, he said suddenly:--

"The inquest will open at three o'clock tomorrow. You will be present, of course, Mr. Grant?"

"I suppose it is necessary."

"Oh, yes. You found the body, you know. Besides, you may be the only person who can give evidence of ident.i.ty. In fact, you and the doctor will be the only witnesses called."

"Dr. Foxton?"

"Yes."

"Has he made a post-mortem?"

"He is doing so now. You see, there is clear indication that this unfortunate lady was struck a heavy blow, perhaps killed, before she was put in the river."

"Good Heavens! Somehow, I was so stunned that I never thought of looking for signs of any injury of that sort."

Grant's horror-stricken air was so spontaneous that it probably justified the severe test of that unexpected disclosure. He was so unnerved by it that the two policemen had gone before he could frame another question.

Once they were in the open road, and well away from The Hollies, Robinson ventured to open his mouth.

"He's a clever one is Mr. Grant," he said meaningly. "You handled him a bit of all right, sir, but he didn't tell you everything he knew, not by long chalks."