“Now I think we’ll go across to where we left my car.”
On the way to the police station Sir Clinton’s manner did not encourage conversation; but as they got out of the car he turned to Armadale.
“Map-drawing’s a bit late in the day now, Inspector; but we may as well carry on for the sake of completeness.”
He led the way to his office, took a ruler and protractor from his desk, and set to work on a sheet of paper.
“Take this point as the museum,” he said. “This line represents the beginning of the tunnel. I took the bearing that time when I lagged behind you. At the next turn—this one here—I made a pretence of examining the walls and took the bearing as we were standing there. I got the third bearing when I asked you to measure the dimensions of the tunnel. As it has turned out, secrecy wasn’t really necessary; but it seemed just as well to keep the survey to ourselves. I got the distances by pacing, except the last bit. There I had to estimate it, since we were crawling on all fours; but I think I got it near enough.”
“And you carried all the figures in your memory?”
“Yes. I’ve a fairly good memory when I’m put to it.”
“You must have,” said Armadale, frankly.
“Now,” Sir Clinton went on. “By drawing in these lines we get the position of that underground room. It’s here, you see. The next thing is to find out where it lies, relative to the ground surface. I had a fair notion; so when I got to the top of the turret I took the bearing of the Knight’s Tower. I’ll just rule it in. You see the two lines cut quite near the cell. My notion is that there’s a second entrance into that tunnel from that ruined tower. In the old days it may have been a secret road into the outpost tower when a siege was going on.”
“I see what you’re getting at now,” Armadale interrupted. “You mean that Maurice Chacewater’s body was in the cell and that it was shifted from there up the other secret passage—the one we didn’t see—and left alongside the tower this morning?”