She raced off after him, vaulting the naked, coughing man and hammering down the walkway behind the avatar. Thin pillars of cerise light flicked into existence, splashing fire from the ceiling. One lanced through the walkway a metre behind Berdle’s flying feet; she jumped the resulting fist-sized hole.

“One right turn at the next junction, steps up dead ahead,” she heard his voice tell her. “I’ll join you momentarily.”

Then the avatar put out a hand, caught hold of one of the walkway’s supporting chains and was lifted off his feet and spun round, just as another pink bolt pierced the walkway immediately ahead of him. He dropped over the side of the walkway, at first falling, then curving away through the darkness and the everywhere roar of water. Light glittered again inside the tank as two shapes rose twisting though the air beneath, filling the space with hair-thin shining filaments.

She put her head down, pounded along the wildly swinging gantry, skidded round the corner at the junction and saw a short flight of steps leading up through the ceiling.

The storm of air howling down through the hole in the ceiling made it almost impossible to make any headway. She needed all four arms to pull herself upwards on the chain bannister rails, and all the strength in her own legs and the suit’s to force her way up the metal steps. Small pieces of debris came hurtling down from above and hit her shoulders or bounced off her head, hurting her even through the thin covering of suit-helmet.

“Ow! Fuck!” she said, though the scream of air tearing around her was so loud she couldn’t actually hear anything else.

She made the deck above, threw herself onto the soft, carpeted floor under subdued lighting and rolled away from the torrent of air being sucked howling into the emptying cavern beneath. Around her – in what looked like a very large, complicated, low-ceilinged room – terrified-looking people were staring wide-eyed at her over the top of luxuriously sculpted pieces of pale furniture. A man and a woman were sitting on a nearby couch, feet braced against the floor, causing rumples in the carpet, their fingers clawing into the soft material of the cushions they sat on. The couch itself was jerking and sliding across the floor, towards the hole. The woman closed her eyes. The man opened his mouth in what was probably a scream but there was too much other noise to tell.

Cossont used all four hands to claw her way across the floor. Something white came whirling towards her; she ducked instinctively as a fat square pillow bounced over her and disappeared into the maelstrom around the aperture in the floor. Where it had come from, twenty metres away, part of the floor gave way and a set of couches and chairs holding maybe a half dozen people disappeared, sucked downwards into the darkness.