“Whose plan?” I said stupidly.

“Hitler’s, of course,” Langby said. “Who did you think I meant?” and, almost casually, picked up his stirrup pump.

The page of the ARP manual flashed suddenly before me. I poured the bucket of sand around the still sputtering bomb, snatched up another bucket and dumped that on top of it. Black smoke billowed up in such a cloud that I could hardly find my shovel. I felt for the smothered bomb with the tip of it and scooped it into the empty bucket, then shoveled the sand in on top of it. Tears were streaming down my face from the acrid smoke. I turned to wipe them on my sleeve and saw Langby.

He had not made a move to help me. He smiled. “It’s not a bad plan, actually. But of course we won’t let it happen. That’s what the fire watch is here for. To see that it doesn’t happen. Right, Bartholomew?”

I know now what the purpose of my practicum is. I must stop Langby from burning down St. Paul’s.

September 28—I try to tell myself I was mistaken about Langby last night, that I misunderstood what he said. Why would he want to burn down St. Paul’s unless he is a Nazi spy? How can a Nazi spy have gotten on the fire watch? I think about my faked letter of introduction and shudder.

How can I find out? If I set him some test, some fatal thing that only a loyal Englishman in 1940 would know, I fear I am the one who would be caught out. I must get my retrieval working properly.

Until then, I shall watch Langby. For the time being at least that should be easy. Langby has just posted the watches for the next two weeks. We stand every one together.

September 30—I know what happened in September. Langby told me.

Last night in the choir, putting on our coats and boots, he said, “They’ve already tried once, you know.”

I had no idea what he meant. I felt as helpless as that first day when he asked me if I was from the ayarpee.