London

His young followers obeyed him instantly, flinging themselves down in the mud and pulling Tom, Wren, and Wolf down with them. There was a faint buzzing sound that grew quickly louder and higher pitched until it passed beyond the reach of human hearing; then a gigantic arc of lightning crackled across a gap between two spires of melted deck plate.

"What was that?" gasped Wren, trying to rub the afterimage off her eyes as crossbow girl helped her to her feet.

"Lingering energy from MEDUSA," said Tom's guard cheerfully. "We call 'em 'sprites.' That one was pretty pathetic compared with the monsters we used to get. In the old days the whole of London was hot."

Chapter 19, The Hollowway Road, A Darkling Plain


After a bit we came over a rise, and there in front of us was a sort of valley stretching right across the middle of the debris field. It looked quite peaceful, with ponds and trees on its floor, but the wreckage on either side was all charred and twisty-looking. Angie says that it's the place where the core of MEDUSA fell, having melted its way right down through the seven tiers of London, and that's why MEDUSA's residue is strongest there. I don't know if it's true. Anyway, I only got a quick glimpse before Angie shoved me into a hollow of the wreckage all overhung with ivy. "Hide!" she said. The stupid old Stalker-bird didn't see us, and went soaring out over the valley. It hadn't gone fifty feet before a great snaggly fork of electricity came crackling out of the wreckage and roasted it; there was nothing left but a puff of smoke and some singed feathers that blew away on the wind!

Darkling plain, pg 307/492, Part 3, Chapter 32, London Journal