At half-past six, Mandrake and Chloris, came into the library with their top-coats over their arms, and asked if they too might leave Highfold.
“Yes,” Alleyn said. “You’ll be asked to attend the inquest, you know, so I’ll have to keep in touch with you.”
“I know,” Mandrake agreed, “we’d thought of that. When will it be?”
“Wednesday, I should think.”
“Jonathan’s asked us to stay but we thought we’d like to go up to London for a slight change of scene. We might look in at the rectory. The road’ll be all right now. Can we take a message for you?”
Alleyn gave his message. Mandrake and Chloris still hung off and on.
“We also thought,” said Mandrake at last, “that we’d like a few of the worst knots unravelled by a master hand. Or doesn’t one ask?”
“What knots?” said Alleyn with a smile.
“Well,” said Chloris, “why Aubrey was shoved in the pond, for one. Did Nicholas shove him?”
“He did.”
“But he recognized Aubrey.”
“Because he recognized him.”
“Oh.”
“But,” said Mandrake, “we’d worked that out quite differently. After the evidence of the footprints and her letter, we decided that Mrs. Compline had followed out to stop Nicholas taking the plunge and had thought I was William gloating and, on a wave of long pent-up resentment, had shoved me overboard.”
“And then,” said Chloris, “we thought that when she heard Bill was dead, she’d gone out of her mind and imagined that in some way she had killed him. That’s how we read the letter.”
“It’s a very ingenious reading,” said Alleyn with the ghost of a smile, “but it doesn’t quite fit. How could she have gone down the steps without your seeing her? And even suppose she did manage to do that, she would have had a very clear view of you, as you stood facing the pond. Moreover she watched William go downstairs. And, finally, she had a full account of the whole affair afterwards and heard you being brought upstairs and all the rest of it. Even if she had pushed you overboard she must have very soon heard of her mistake, so how on earth could she think she’d killed William?”
“But the letter?” said Chloris.
“The letter is more tragic and less demented than you thought. The evidence of the footprints tells us that Mrs. Compline stood on the terrace and looked down. A few moments later a housemaid saw her return looking terribly upset. I believe that Mrs. Compline saw her son Nicholas make his assault upon you, Mandrake. At the time she may have thought it a dangerous piece of horseplay, but what was she to think when she heard him declare that Hart had done it, believing the victim to be Nicholas himself? And what was she to think when the booby-trap was set and again Nicholas accused Hart? Don’t you think that through the hysteria she displayed, ran some inkling of the truth? Last of all, when Nicholas went to her last night and told her William had been killed in mistake for himself, what was she to think then? With her secret knowledge how could she escape the terrible conclusion? Her adored son had murdered his brother. She made her last effort to save him and the legend she had made round his character. She wrote a letter that told him she knew and at the same time accused herself to us. She could not quite bring herself to say, in so many words, that she had killed her son; but Nicholas understood — and so did we.”
“I never thought,” said Mandrake after a long silence, “that Nicholas did it.”
“I must say I’d have thought you’d have guessed. Compline gave you the cape, Mandrake, didn’t he? He looked out of the pavilion window and recognized you as you came down. He might have been looking at himself when you stood there in the other cloak. I think at that moment he saw his chance to bring off his tom-fool idea.”
“What tom-fool idea?”
“To stage a series of apparent attempts on his own life based on an idea of mistaken identity. He planted that idea in all your heads. He insisted on it. He shoved you in and rescued you and then went about shouting that Hart had tried to drown him. Evidently he’d some such plan in his head on the first night. Hart had written threatening letters and Compline followed up by writing himself a threatening message with a rather crude imitation of Hart’s handwriting. Once we’d proved Hart didn’t write the message on the Charter form it was obvious only Nicholas could have done so. Perhaps he chucked you that cape deliberately. Before the bathing incident he knew where you all were and no doubt he watched Hart set off alone down the drive. If the plan failed there wasn’t much harm done. Next, he staged his own flight over country that he knew damned well was impassable. If nobody had gone with him he’d have come back half-drowned in snow and told the tale. Next he rigged up his own booby-trap, choosing a moment when you were all changing in your rooms. He hadn’t bargained on Madame Lisse looking after him as he went down the passage. He was going to kick the door open and let the brass Buddha fall on the floor. But, knowing that she was watching, he had to go a bit further than was comfortable, and he mucked up the business. He chose the Buddha because he’d seen Hart handle it the night before. He chose the Maori mere for the same reason, but he smudged Hart’s prints when he used it. He himself wore gloves, of course.”
“But the wireless?” asked Chloris.
“Do you remember that Hart had complained bitterly of the wireless? That appears in Mandrake’s most useful and exhaustive notes. Compline knew Hart loathed radio. After the fiasco at the pond he shut himself up in the smoking-room, didn’t he, until he was turned out by William, who wanted to make his drawing? And discordant noises were heard? He was always at the radio? Yes; well, he was making himself very familiar with that wireless set. Do you remember the fishing-rod above the mantelpiece in the smoking-room?”
“Yes,” they said.
“Complete with fly and cast and green line?”
“Yes.”
“Well, when we came on the scene there was no fly and the line had been freshly cut. On the screw-hole on the volume control I found a number of almost invisible scratches, all radiating outwards. I also found some minute fragments of red and green feathers. The card on the rod tells us that the late Mr. St. J. Worthington Royal used that red-and-green fly when he caught his four-and-a-half-pounder. There were other marks on the double tuning control which, at its centre, was free of dust. In the jamb of the door into the library there was a hole which accommodated the drawing-pin Mandrake picked up in the sole of his shoe. You saw that William dropped one of his drawing-pins in the smoking-room. I fancy Nicholas found and used it. In Mrs. Compline’s hat I found two flies, one red-and-green, rather the worse for wear. The maid who looked after her swears there was only one, a yellow-and-black salmon fly, when she arrived. Who went straight to his mother’s room after the murder? Right,” said Alleyn, answering their startled glances. “Well, yesterday evening we experimented. We found that if we used a length of fishing-line with a fly attached but without a cast, we could hook the fly in the screw-hole of the volume control, pass the green line under the wave band and over the tuning-control axis, which served as a sort of smooth-running pulley, and fix the other end of the line to the library doorjamb with a drawing-pin. When you tweaked the line the hook pulled the volume control from Zero to fairly loud, the line playing over the tuning control, which we had set in such a way that the slight pull turned it to the station. As the hook in the screw-hole reached the bottom of the circuit, it fell out and the wireless was giving tongue.”