There was a shocked reaction from the listeners at this.
“I guess that even after sticking a knife in a victim’s heart a murderer feels anxious. They can’t know whether the victim is really dead. There was no time for me to set up the snow-under-the-lock trick. I wanted to get out as quickly as possible.”
“So when you set up the locked room, did you use the shot-put like that student said the other day?” Ushikoshi asked.
“That’s right.”
Kiyoshi took up the story again.
“But even if you say it’s because you’d lost your mind, by tying that cord around the victim’s wrist, it made it quite obvious that the killer had been inside the locked room. But you didn’t go into the next locked room at all, did you? That managed to create all kinds of confusion for the detectives.
“Anyway, as he was dying, Ueda realized that he could move his wrist and tried to leave a message. If he lifted both hands up over his head in a V-shape, he could make the Japanese semaphore signal for ‘ha’. In Japanese semaphore most syllables require two separate placings of the flags, but ‘ha’ just happens to need only one.
“But the problem with ‘ha’ alone, is that it might not only signify Hamamoto. It could just as easily have meant Hayakawa. So he needed to signal ‘ma’ as well to make it clear who he meant. Unfortunately, it takes two placements of the flags to make a ‘ma’—the right arm horizontally out to the side with the left arm placed thirty to forty degrees below it, or pointing diagonally downwards; followed by a dot where you cross the flags above your head. However, it was impossible to recreate these two separate placements in one single move, not to mention that he was already signalling ‘ha’ with his arms.
“But of course he had his legs. Semaphore is created using flags which are held in both hands, but Ueda decided to use his legs to create a ‘ma’. That’s why his legs are pointing at that strange angle, and the circular spot of blood on the floor beside him is the dot. That was the meaning of the blood spot and the ‘dancing corpse’. I checked out semaphore signals in the encyclopaedia in the library yesterday evening.
“And then we come to the murder of Eikichi Kikuoka—”
“Hold on a minute!” I said. “There are still so many questions about the first murder.”
I wasn’t the only one who felt that way. Several other people began calling out. It was typical of Kiyoshi to skimp on the details when he’d already worked everything out for himself.
“What about those two stakes stuck in the snow?”
“And the doll that looked in through my window?”
“And the scream that came thirty minutes after the murder? What was that?”
“Ah, yes, those things. Where to begin? Well, they’re all connected. Kazumi, you’ve worked out the meaning of the stakes by now, surely? So as not to leave footprints in the snow you could walk backwards in a crouching position, erasing them with your hands as you went. As long as you took the exact same path going back as the one you took when you came. But that method isn’t perfect and too easy to spot. So what’s an alternative? The easiest is to make it snow again, just in the area where your footprints are.”
“And how do you do that? Beg it to snow? And only where you’ve been walking?”
“You do it the opposite way around. You only walk in the places where you can get it to snow.”
“What? I’m still asking you how you get it to snow.”
“From the roof. You make it snow from the roof. And as luck would have it, that night it was covered in powder snow. Normally, as long as it isn’t blown off by the wind, when snow falls off a roof it lands directly under the eaves. But this house is built on a slant and leans to the south. When the snow falls off this roof it lands about two metres away from the eaves.”
“Aha!” said Ushikoshi.
“Mr Hamamoto had to be careful. The snow would only land in a parallel line to the roof, so that was the only place he could step. The best thing was for him to mark the line and go and return along that exact same route. But drawing the line in the snow would be way too much trouble. And if it happened to snow that evening, the line would disappear. So that’s the reason. You get it now?”
“I still don’t get it. Why put stakes in the ground?”
“As markers! Instead of drawing a line. The imaginary line between those two stakes was the exact position of the edge of the roof. In other words, the route that he needed to walk. It would be hard to see your own footprints at night, but on his way there he could aim for the stake at the west end of the house, and on his return the east one. On the way back he would have tried to erase his footprints a little bit I assume. Of course, he would also have pulled out the stakes and taken them with him, then burned them in the fire.
“Of course, he wouldn’t have had to bother with all that if it had been snowing when he killed Ueda, but it was a precaution in case the snow stopped falling—and it had stopped that night, so he made use of his trick.”
“So you are saying that after killing Ueda he climbed on the roof and knocked the snow off it?”
“Yes. He made it snow.”
“I see.”
“Next—”
“Just a minute! What about the doll that was found in pieces near Room 10? Why was it there? Was it used for something?”
“It’s obvious, isn’t it? That was the place where he couldn’t make it snow. He could only make the snow fall by the edge of the roof.”
“Huh? So that means… Er, what does that mean? Something to do with the problem of the footprints…”
“When he climbed the steps to Room 10 he could walk along the edge where the handrail overhangs and not leave any footprints. The problem was the bit between the west corner of the house and the bottom of the steps. There was no way of hiding prints. So he put the doll down in the snow and walked over it.”
“Aha!”
“But if he just placed it there as it was, it wouldn’t be enough to cover the distance between the edge of the roof and the stairs, so he disassembled it and spread the pieces across the space. Then he walked across it like stepping stones.”
“Ah!”
“That’s why he chose a doll that could be taken apart.”
“Why didn’t we think of something so simple? But… The doll looked in through Ms Aikura’s window. Was that before…? Or…?”
“Yes, well, that was only the head. Now as to why he had to do that—”
“I think perhaps I should explain this part,” said Kozaburo, noticing that Kiyoshi was getting a little impatient.
“It’s just as Mr Mitarai said. I walked over the doll’s body, used the stakes in the ground as landmarks and roughly levelled out the snow to cover my footprints as I went back inside the house to head up to the roof. But I was still carrying Golem’s head at that point. I planned to return the head to Room 3 and then quietly wait for morning, hiding either in Room 3 or in the library next door.
“Because everyone thought I had gone to bed in my room in the tower, I couldn’t risk making all the noise of lowering the drawbridge until it was a believable hour in the morning for me to be getting up. I planned to wait until around 7 and then open it, pretending I had just woken up.
“I was still carrying the head because I didn’t want it to get damaged from lying out in the snow overnight. I had thought about dropping off the head in Room 3 first, but then I decided as I was going there later to wait out the night anyway, it was probably best not to go back and forth too many times and increase the possibility of being seen. So I was carrying it when I climbed the ladder on the side of the main building up to the roof. Earlier I had left the door end of the drawbridge slightly ajar, just enough for me to slip out through and then later get back in.