Aziraphale would find it quite impossible to walk out the door with the warhead. Adam made sure of that.

"They're safer here than anyplace," he said resolutely, ignoring the angel's snide tone. He really had been around Crowley too much. "It makes War happy to have them around, and I won't let them get used. I can't say the same for any humans who find them wherever you were thinkin' of hidin' them. You don't really think I stopped a world-wide nuclear war last time just to let another one start by accident right under my nose, do you?"

Really, being the adult was tiring sometimes.