The admiral stepped forward, blinking rapidly. “A bombing raid. He knew I would send a team with you, yes, and didn’t care. The more we send in, the more who would die with you when those bombs fell.”

“While I leave the codebook a safe distance away.” Drake’s lips had gone thin and tight. He motioned to Hall. “I told him about that part, too, of course.”

“And I agree that our so-dubbed Emergency Code is the perfect answer. Compromising it is no great thing at all.”

Margo had expected nothing else. She stood and moved to look over Drake’s shoulder. “What’s the target?”

He tapped a finger to the map. “It’s the Woolwich munitions factory.”

Her muscles went still, frozen for a moment. Even if only a few planes made it, even if only a few bombs fell, that would be catastrophic. It wouldn’t take much to turn the factory itself into a bomb, killing not only Dot but innocents by the hundreds. Perhaps the thousands. “No.”

Drake pushed away from the table. “It isn’t enough to just go in and get Dot out. We have to stop them. Not just him, but them. How do we do that?”

Culbreth and de Grey had both given up their own work and had gathered round the map. Culbreth tapped something near the mouth of the Thames. “We alert the RFC and RNAS, for starters. There’s no great risk to our operations in telling them—the Germans won’t know they’ve tipped us off, they’ll just assume we had a scout in the air who spotted them. Then we can get our own lads up in the air to take out as many as they can and get the antiaircraft guns ready.” He lifted his brows in Hall’s direction.

DID nodded. “Do it.”

Culbreth spun for the door.

De Grey turned that way too. “And we can have them sound the sirens in that part of London. The residents ought to have ample time to get to the underground shelters and out of the city.”

Hall was still nodding. These were safe actions, precautionary ones. Actions that, as Culbreth had pointed out, wouldn’t alert the German High Command to the fact that they’d broken their codes and thereby inspire them to change them entirely. They would assume the Gothas had been spotted. Room 40’s secrecy would be upheld.

Even so. When other squadrons that large had made their way across the Channel, their defenses hadn’t succeeded in blocking them all. A few always slipped through. And though their bombs hadn’t seemed to be aimed at specific targets, with detailed information like what Dieter Regnitz had provided, that would change.