Fire and disintegration beams slashed into the Nightstalkers, scattering their formation. Ancient beakers and bottles exploded into shards of glass, and clouds of smoke and steam covered the laboratory. A blast from Cinder sent Lee stumbling aside, beating at the flames licking up his arm. Dhruv stepped up to fill the gap, face pale, his metal disc rotating vertically to block a gout of flame from Cinder as gold-hair girl sent ground fire back. Cinder kept up the stream of flame for a second then changed the spell; the fire narrowed, intensified, as if being focused through a lens, becoming a white-hot beam only an inch or two wide. The beam cut through Dhruv’s disc, the metal flashing red-yellow-white as it liquefied, molten drops splashing to the floor before the beam sawed through Dhruv’s arm and into his side. Dhruv had time for one scream, then his body caught fire from the inside out and he became a flaming torch, thrashing and falling.

The Nightstalkers broke and ran. Will was still shouting, but no one was listening anymore. I caught a glimpse of Captain America and Lee sprinting for the exit leading to the duelling hall; gold-hair girl was running for the tunnel mouth in which I’d placed my forcewall. Will saw that he was the only one still fighting, jumped out of the way of another disintegration ray, and sprinted after gold-hair girl, rapidly outpacing her.

I’d had a couple of seconds’ head start and was already running for the exit that Will and the girl had chosen. In the smoke and chaos they didn’t realise it was me and for one bizarre moment we were running together. I made it through the archway first, with Will right behind. Before gold-hair girl could follow I shouted the command word. The forcewall snapped up and gold-hair girl slammed into the invisible barrier, staggering back with a bloody nose. Will whirled, looking to see where she’d gone.

Gold-hair girl was left alone in the laboratory, cut off by the forcewall. The heavy tread of booted feet sounded from behind her, and she turned.

Cinder came out of the smoke, a hulking silhouette outlined in red flame, eyes shadowed in the darkness. He looked like a demon of the underworld and gold-hair girl shied away, sending a blast of ground fire at him. The flame raced towards Cinder, engulfed him in a roaring blaze. For an instant he was hidden, then he strode out with fire licking at his legs and clothes. He hadn’t even slowed down. Gold-hair girl threw up her hands. “Wait, don’t! Please!”