Finally, after squeezing between the Lightning and a tarp-shrouded jet engine on a trolley I fetch up where I started from, back by the workbench. "Last words." I pick up the microphone that's plugged into the signal generator, flip the switch, and say, "Piss off."

There's a bang and a blue flash from the grounding point on the airframe, and my PDA makes an ominous crackling noise. Then the thaum field dies. "You nailed it," says Hastings.

"Looks that way," I agree, turning to face him.

He looks past me. "What about the—Hey, what are you—"

Now here's where things go wrong.

Muggins here didn't bother to set up a ward around the workbench with the contaminated cockpit console before he sorted out the airframe, because he thought that he could do the two jobs separately. But they're not separate, are they? The law of contagion applies: the cockpit instruments had been physically bolted to the airframe for a number of years, and things that form a unitary identity for a long time tend to respond as one.

More importantly, nobody had thought to tell Muggins precisely what Squadron 666, Royal Air Force, did with its planes. Escorting the white elephants. Muggins here still thought he was dealing with a simple spontaneous haunting—bad memories, terrified pilot in near-death experience, that sort of thing—rather than secondary activation caused by overexposure to gibbering unearthly horrors; the necromantic equivalent of collecting fallout samples by flying through mushroom clouds.

But I'm second-guessing the enquiry now, so I'll shut up.

Warrant Officer Hastings survives the explosion because he is still inside his protective pentacle.

Muggins here survives the explosion because he is wearing a heavy-duty defensive ward around his neck and, in response to Hastings's call, has turned to look at the open doorway where little old Helen with her tightly curled white hair is standing, clutching a tea tray.

Her mouth is open as if she's about to say something, and her eyebrows are raised.

I will remember the expression on her face for a very long time.

Beauty may be skin-deep, but horror goes all the way down to the desiccated bone beneath, as the eerie purple flashbulb glow rises and her eyes melt in their sockets and her hair and clothes turn to dust, falling down and down as I begin to turn back towards the airframe and reach for the small pouch around my neck, which is scalding hot against my skin as the air heats up—

There's a dissonant chime from the signal generator on the bench, unattended, then a continuous shrill ringing alarm as its safeties trip.

The hideous light goes out with a bang like a balloon bursting, a balloon the size of the Hindenburg.