H. M. had lost his woodenness. His voice smashed across the silent room.
"Didn't I tell you that somebody had smashed a decanter and a couple of glasses on the hearthstone; deliberately smashed 'em, to make it look like there'd been a struggle there? Well, didn't you wonder why? It was to offer proof she'd been killed at the pavilion.
"Now I'm very slowly and painstakingly goin' to tell you what he did. He didn't kill the woman. He found her dead when he got here. And in this tale you'll probably see the dead glarin' evidence that'll tell you who did kill her. Go back to the beginning of it all.
"She left that pavilion, turnin' off the lights; she came up here, as I've told you, and was afraid to go back because of the dog. Now in the tale I'll leave a single cloud of blackness straight in the middle; the cloud of blackness that hides the murderer who finds her here and beats her head in. The murderer leaves her here — maybe on that bed," he pointed: "maybe anywhere. We pass the cloud of blackness to the end of the story, when John Bohun comes into it.”
"He's driven back from town. He thinks he's killed Canifest, and the only thing that will save him is to lie about the time he reached home. That is, if he can somehow prove that he did reach home at the same time he must have killed Canifest in London; if he can prove an alibi by having somebody swear he was here and not in London when Canifest died; that'll save him. That's simple, ain't it? He's got to get that alibi. It's burnin' in his mind all the time he rides hell-for-leather out here. Fix it! Fix it, somehow! So that wild, nervous, irresolute feller who don't know his own mind from one minute to the next he comes home, walks up here, and finds Marcia Tait dead in his room!
"Look here, do you wonder much at his behavior this mornin'? Here he was, caught between two hangmen as neat as you please. Now if he fakes an alibi, and says he couldn't have been with Canifest because he was here, he's got a dead woman in his room to account for. If he admits the time he got home, they may hang him for Canifest's death. Whichever way he looks, there's a hemp collar swingin' at the end of it. He don't know who killed Tait. He don't even know how she got here, or anything about it. What he does know is that he's in a hell of a mess, and he's got to see a way out so that he won't swing for either crime.
"Could he, for instance, carry her back to her own room and pretend she'd been murdered there? Then he could swear to a faked time at which he got home; and maybe get somebody to back him up. Where was she supposed to sleep? He remembers: the pavilion. Did she go out there? He's got to find out, and there's nobody awake to tell him. He also remembers: a riding-engagement for this morning.
"The thing to do is find out. Now here's where the grain of truth in Rainger's theory enters. He dresses in riding-clothes, so that if she really has slept at the pavilion (as he believes), he'll have a good excuse for `finding' her early in the morning. He wakes up the butler, who tells him she's out there and that horses are ordered for seven o'clock. Good God! There's where the ticklish, dangerous skatin' on ice comes in. The stables are in sight of the pavilion and even the door of the pavilion! If he delays until quite daylight, somebody bringin' those horses out may see him go down with the body… On the other hand, if he can take her in there a few minutes, just a few minutes beforehand; if he can put her in the bedroom, and then walk back to the front door of the pavilion; then stand there until he sees somebody at the stables, whom he'll hail as though he were just goin' in for the first time to `find' her — then he's safe."
H. M. stabbed out with his finger. "Do you understand the burnt matches now? He carried her in there and put her on the floor a few minutes before Jim Bennett unexpectedly arrived on the scene: so few minutes that his tracks were still fresh. It was growing daylight, but not quite daylight (I carefully asked that nephew of mine about it) and Bohun had to be able to see clearly to set his stage for the fake murder! Got it now? He didn't dare switch on a light in the room. A large window faced directly towards the stables, where people were already up. If a light flashed on in that room, sorta sudden and inexplicable-like, a few minutes before Bohun claimed he walked into the pavilion for the first time. why, somebody would have seen it and wondered why."
"Hold on, sir!" said Bennett. "There was a blind on that window — a Venetian blind. Couldn't he simply have lowered the blind?"