He brought the Enigma machine to Windyedge. He flew the plane we didn’t find when we tangled with the Messerschmitt 109 in November; I’d imagined him as a lost wingman, but he turned out to be a resistance agent who somehow eluded the fighter chasing him.

Can you hear me?

I hear nothing.

Was it also Felix Baer whistling an SOS in the Junkers 88 we let go on Christmas Day?

I wondered about him. I wondered what he’d risked to get that cipher machine over here.

I wondered if he guessed we were using it.

As our intelligence officer, Phyllis surely already knew a bit about “Odysseus’s” visit to Windyedge. Ellen softened her up between the Blenheims and the operations hut, confessing how the rogue German pilot held her hostage; how he spent the night at the Limehouse going through Mrs. Warner’s record albums; how Louisa recognized the whistled tune during our North Sea Christmas party, the same music he played on the piano in the pub that night.

Incredibly, when we got to debriefing, Phyllis was as prim and neat in her uniform as if she’d never been off the ground.

“It feels terribly odd to ask you to tell me in the usual way what happened up there, when I saw it all myself,” she said apologetically. “But what happened up there?”

B-Flight lined up on their folding chairs, except Dougie Kerr, who was still hovering hopefully over the tea trolley as if he expected more shortbread to magically appear.

Hiding in plain sight seemed safest. I’m a quick liar, but not always a consistent one. I wanted to tell everyone the same story, and keep it simple, so I took on Phyllis and B-Flight at the same time.

“We weren’t ever going to be heroes during a Christmas Day cease-fire,” I answered Phyllis. “But there was a good reason not to go after that Luftwaffe bomber today.”

I turned around, leaning over the back of my chair, to include Pimms and Madeira.

“A German resistance team left Windyedge a list of upcoming U-boat maneuvers last November—that’s why we’ve had such good hunting this month. We know where a few of them are going to turn up. That whistler on board the Ju-88 is probably the man who left the tip-off.”

There was a murmur of comprehension as B-Flight fit this with what they already knew.

“So you lads keep quiet about what you heard today and don’t second-guess the next mission, fair enough? We’re privileged to have this information, thanks to a brave man from the other side. We’re on our way to being aces.”

They straightened in their seats.

Beside me, Silver fiddled with his box of rosin, grinning down at it.

I didn’t have to mention the coding machine.