Poirot turned his head very slowly and looked at the secretary. Those last words had been uttered too hastily. He formed the conviction that Trefusis could have said more had he wished to do so. But once again Poirot did not press the question.

"And then? Proceed, I pray of you."

"I worked with Sir Reuben for about an hour and a half. At 11 o'clock Lady Astwell came in, and Sir Reuben told me I could go to bed."

"And you went?"

"Yes."

"Have you any idea how long she stayed with him?"

"None at all. Her room is on the first floor, and mine is on the second, so I would not hear her go to bed."

"I see."

Poirot nodded his head once or twice and sprang to his feet.

"And now, Monsieur, take me to the Tower room."

He followed the secretary up the broad stairs to the first landing. Here Trefusis led him along the corridor, and through a baize door at the end of it, which gave on the servants staircase and on a short pa.s.sage that ended in a door. They pa.s.sed through this door and found themselves on the scene of the crime.

It was a lofty room twice as high as any of the others, and was roughly about thirty feet square. Swords and a.s.segais adorned the walls, and many native curios were arranged about on tables. At the far end, in the embrasure of the window, was a large writing table. Poirot crossed straight to it.

"It was here Sir Reuben was found?"

Trefusis nodded.

"He was struck from behind, I understand?"

Again the secretary nodded.

"The crime was committed with one of these native clubs," he explained. "A tremendously heavy thing. Death must have been practically instantaneous."

"That strengthens the conviction that the crime was not premeditated. A sharp quarrel, and a weapon s.n.a.t.c.hed up almost unconsciously."

"Yes, it does not look well for poor Leverson."

"And the body was found fallen forward on the desk?"

"No, it had slipped sideways to the ground."

"Ah," said Poirot, "that is curious."

"Why curious?" asked the secretary.

"Because of this."

Poirot pointed to a round irregular stain on the polished surface of the writing table.

"That is a blood stain mon ami,"

"It may have splattered there," suggested Trefusis, "or it may have been made later, when they moved the body."

"Very possibly, very possibly," said the little man. "There is only the one door to this room?"

"There is a staircase here."

Trefusis pulled aside a velvet curtain in the corner of the room nearest the door, where a small spiral staircase led upward.

"This place was originally built by an astronomer. The stairs lead up to the tower where the telescope was fixed. Sir Reuben had the place fitted up as a bedroom, and sometimes slept there if he was working very late."

Poirot went nimbly up the steps. The circular room upstairs was plainly furnished, with a camp bed, a chair and dressing-table. Poirot satisfied himself that there was no other exit, and then came down again to where Trefusis stood waiting for him.

"Did you hear Mr Leverson come in?" he asked.

Trefusis shook his head.

"I was fast asleep by that time."

Poirot nodded. He looked slowly round the room.

"Eh bien!" he said at last. "I do not think there is any thing further here, unless - perhaps you would be so kind as to draw the curtains."

Obediently Trefusis pulled the heavy black curtains across the window at the far end of the room. Poirot switched on the light - which was masked by a big alabaster bowl hanging from the ceiling.

"There was a desk light?" he asked.

For reply the secretary clicked on a powerful green-shaded hand lamp, which stood on the writing table. Poirot switched the other light off, then on, then off again.

"C'est bien! I have finished here."

"Dinner is at half-past seven," murmured the secretary.

"I thank you, M. Trefusis, for your many amiabilities."

"Not at all."

Poirot went thoughtfully along the corridor to the room appointed for him. The immovable George was there laying out his master's things.

"My good George," he said presently, "I shall, I hope, meet at dinner a certain gentleman who begins to intrigue me greatly. A man who has come home from the tropics, George. With a tropical temper - so it is said. A man whom Parsons tries to tell me about, and whom Lily Margrave does not mention. The late Sir Reuben had a temper of his own, George. Supposing such a man to come into contact with a man whose temper was worse than his own - how do you say it? The fur would jump about, eh?"

"'Would fly' is the correct expression, sir, and it is not always the case, sir, not by a long way."

"No?"

"No, sir. There was my Aunt Jemima, sir, a most shrewish tongue she had, bullied a poor sister of hers who lived with her, something shocking she did. Nearly worried the life out of her. But if anyone came along who stood up to her, well, it was a very different thing. It was meekness she couldn't bear."

"Ha!" said Poirot, "it is suggestive - that."

George coughed apologetically.

"Is there anything I can do in any way," he inquired delicately, "to - er - a.s.sist you, sir?"

"Certainly," said Poirot promptly. "You can find out for me what color evening dress Miss Lily Margrave wore that night, and which housemaid attends her."

George received these commands with his usual stolidity.

"Very good. sir, I will have the information for you in the morning."

Poirot rose from his seat and stood gazing into the fire.

"You are very useful to me, George," he murmured. "Do you know, I shall not forget your Aunt Jemima?"

Poirot did not, after all, see Victor Astwell that night. A telephone message came from him that he was detained in London.

"He attends to the affairs of your late husband's business, eh?" asked Poirot of Lady Astwell.

"Victor is a partner," she explained. "He went out to Africa to look into some mining concessions for the firm. It was mining, wasn't it, Lily?"

"Yes, Lady Astwell."

"Gold mines, I think, or was it copper or tin? You ought to know, Lily, you were always asking Reuben questions about it all. Oh, do be careful, dear, you will have that vase over!"

"It is dreadfully hot in here with the fire," said the girl. "Shall I - shall I open the window a little?"

"If you like, dear," said Lady Astwell placidly.

Poirot watched while the girl went across to the window and opened it. She stood there a minute or two breathing in the cool night air. When she returned and sat down in her seat, Poirot said to her politely: "So Mademoiselle is interested in mines?"

"Oh, not really," said the girl indifferently, "I listened to Sir Reuben, but I don't know anything about the subject."

"You pretended very well, then," said Lady Astwell. "Poor Reuben actually thought you had some ulterior motive in asking all those questions."

The little detective's eyes had not moved from the fire, into which he was steadily staring, but nevertheless, he did not miss the quick flush of vexation on Lily Margrave's face. Tactfully he changed the conversation. When the hour for good nights came, Poirot said to his hostess: "May I have just two little words with you, Madame?"

Lily Margrave vanished discreetly. Lady Astwell looked inquiringly at the detective.

"You were the last person to see Sir Reuben alive that night?"

She nodded. Tears sprang into her eyes, and she hastily held a black-edged handkerchief to them.

"Ah, do not distress yourself, I beg of you do not distress yourself."

"It's all very well, M. Poirot, but I can't help it."

"I am a triple imbecile thus to vex you."

"No, no, go on. What were you going to say?"

"It was about 11 o'clock, I fancy, when you went into the Tower room, and Sir Reuben dismissed Mr Trefusis. Is that right?"

"It must have been about then."

"How long were you with him?"

"It was just a quarter to twelve when I got up to my room; I remember glancing at the clock."

"Lady Astwell, will you tell me what your conversation with your husband was about?"

Lady Astwell sank down on the sofa and broke down completely. Her sobs were vigorous.

"We - qua - qua - quarreled," she moaned.

"What about?" Poirot's voice was coaxing, almost tender.

"L - l - lots of things. It b - b - began with L - Lily. Reuben took a dislike to her - for no reason, and said he had caught her interfering with his papers. He wanted to send her away, and I said she was a dear girl, and I would not have it. And then he s - s - started shouting me down, and I wouldn't have that, so I just told him what I thought of him.

"Not that I really meant it, M. Poirot, and he said he had taken me out of the gutter to marry me, and I said - ah, but what does it all matter now? I shall never forgive myself. You know how it is, M Poirot, I always did say a good row clears the air, and how was I to know someone was going to murder him that very night? Poor old Reuben."

Poirot had listened sympathetically to all this outburst.

"I have caused you suffering," he said. "I apologize. Let us now be very business-like - very practical, very exact. You still cling to your idea that Mr Trefusis murdered your husband?"

Lady Astwell drew herself up.

"A woman's instinct, M. Poirot," she said solemnly, "never lies."

"Exactly, exactly," said Poirot. "But when did he do it?"

"When? After I left him, of course."

"You left Sir Reuben at a quarter to twelve. At five minutes to twelve Mr Leverson came in. In that ten minutes you say the secretary came down from his bedroom and murdered him?"

"It is perfectly possible."

"So many things are possible," said Poirot. "It could be done in ten minutes. Oh, yes! But was it?"

"Of course he says he was in bed and fast asleep," said Lady Astwell, "but who is to know if he was or not?"

"n.o.body saw him about," Poirot reminded her.

"Everybody was in bed and fast asleep," said Lady Astwell triumphantly. "Of course n.o.body saw him."

"I wonder," said Poirot to himself.

A short pause.