Ivanov saw the lights in the lift flicker as the Tower’s emergency power cells took over. They were just passing the nineteenth floor.

Down in the basement, the possessed were smashing every communications conduit they could find, tearing the cables out of the wall. The AI watched the Tower’s net connections fail one after the other. Independent power cells kept the internal processors running, but it could now only access them through the communications blocks carried by the GSDI field agents, cutting down on the bandwidth available for surveillance and initiating possible counter-moves.

Security sensors on the ground floor showed fifteen possessed running up the stairs into the lobby. They immediately started slinging small bolts of white fire at the sensors and any other electronic system. Just before the last camera failed, Charlie saw a lift door being broken down with considerable force.

Out,he ordered. Get out of the lift.

The AI had already established a link to the lift’s controlling processor. It applied the failsafe brakes and slammed it to a halt on the thirteenth floor.

Louise yelped in shock as the lift floor abruptly tried to shunt its way upwards, accompanied by a strident alarm siren. She grasped at the handrail as she lurched against the wall.

The doors flashed open. Charlie was datavising orders to her as Ivanov was shouting: “Move it! The possessed are coming.” Everyone charged out into the corridor. Black apartment doors lined both walls. Smoked-glass windows at either end let in a murky glow from the setting sun. Emergency lights shone brightly above both of the stairwell doors.

Charlie told one of the GSDI agents to leave his communication block in the corridor, tucking it away unobtrusively in a doorway, enabling the AI to maintain contact with the tower’s net. “The possessed are now heading up both stairwells,” Charlie datavised. “Five in one, four in the other. The remainder are waiting downstairs. You’ll have to shoot your way through them. I suggest you use the anti-memory where possible.”

“Gets my vote,” Ivanov said. He drew the small weapon, holding it in his left hand. His right held a compact automatic pistol.

Fletcher and Louise drew their own weapons. The agents and Brent were checking their machine guns.

Ivanov opened the stairwell door cautiously. Concrete steps with metal rails wound down the shaft in a rectangular corkscrew. The sound of running boots echoed upwards.

“They know we’re here,” Fletcher said curtly.

The AI tracked glitches rising up the stairwell and computed the approximate distance. Both GISD field agents entered the time into the trigger mechanism on their grenades and dropped them down the shaft.

Louise hunched down next to the wall, her hands pressed against her ears. Explosions roared below as the chemical shrapnel grenades detonated. Then the agents tossed their gas incendiaries over the rail. Billows of flame scoured the battered stairs, searing against the groggy possessed. Screams trilled along the length of the stairwell.

“Let’s go,” Ivanov said. He took off down the stairs.

Louise was third in line, behind one of the agents, with Brent pounding along behind her. She’d put a host of programs in primary mode, an auto-locomotion so she could tear round the stairwell corners without slipping, adrenaline suppresser working through the medical nanonic to keep her calm, weapons control so she’d be able to aim the anti-memory tube properly, peripheral motion analysis, heart-rate control as a counter to the adrenaline suppresser, making sure her straining muscles received enough blood, tactical analysis, which was synchronized with the AI. It informed her that possessed from the lobby were starting to invade the bottom of the stairwell in support of their injured comrades. After descending another two floors, the agents would drop more grenades, and they’d all switch stairwells.

A thick streamer of white fire plunged up the centre of the stairwell, its tip swelling rapidly.

Louise flung herself back from the rail. Brent and one of the agents stuck their machine guns over the edge, shooting off a suppressing deluge of static bullets.

The plume of white fire burst open, spitting out a shower of incandescent sparks. Several of them landed on Louise’s legs, stinging hard as they burnt their way through her leggings. She batted at them with her free hand, putting an axon block in primary to dull the pain. Her tactical program was urging her up. Neuroiconic icons began to flash warnings about capacity reduction in her neural nanonics.

A bolt of white fire flashed like lightning. It hit the GSDI field agent who was covering the rear of the group, penetrating straight through the back of his skull to char the brain. He crumpled instantly.

Ivanov and the remaining agent whirled round, their weapons trying to find a target.

“Where the fuck did that come from?” Brent yelled.

Charlie knew there was only one answer. Instinctively, his affinity bond made Ivanov turn to face Fletcher. “Well?” the detective demanded.

“He is here,” Fletcher said with trepidation. “I feel him even though he hides beyond sight.”

The possessed were clattering up the stairwell again. Neural nanonics and blocks were beginning to glitch.

Charlie tightened Ivanov’s grip around the anti-memory weapon. “Through here,” he ordered. Ivanov went through the door to the tenth floor, arm swinging in wide arcs to cover the corridor. It was deserted, a copy of the thirteenth floor. Louise and Brent followed him while the last agent dropped a couple of grenades over the rail. They all started to run for the second stairwell. The grenades didn’t go off.

“Is he still here?” Ivanov asked.

“Close,” Fletcher said. Fury and frustration boiled into his voice. “I cannot see him. The devil!”

“Shoot it where you think he is. It might work anyway.”

Fletcher stopped running and lifted the anti-memory weapon, his thumb pushing the trigger button forwards. He glanced about the sombre corridor as though trying to make his mind up. The trigger was suddenly pressed, sending a cone of bright ruby laser light stabbing out.

“It is useless,” Fletcher cried. “Useless.”

The energistic glitch had crashed just about all of Ivanov’s neural nanonics. He certainly couldn’t receive any datavises. That meant the possessed were very close now.

The AI has lost all contact with the communication blocks,charlie said. I can’t track the possessed for you any more.

Up is no good,ivanov said. he looked round wildly. We’ll have to make a stand.

Very well. There’s a chance Dexter will become visible during the fight. If that happens, you must fire the anti-memory no matter what the cost.

You won’t even have to compel me. Finishing the shit will be my pleasure.

Fletcher had put his arm protectively around a trembling Louise. He suddenly fired the anti-memory again, sending the beam over Brent’s head.

“Careful with that thing,” Brent shouted.

Fletcher ignored him. “The others are almost here.”

Three machine guns lined up on the stairwell door.

“Get away,” Ivanov told Louise, waving her towards the window at the end of the corridor. Then he saw what was behind her, and let out a fast yell of delight. “Yes! Oldest trick in the book. Fletcher, cover for me. We can get her out.” You should have thought of this,he accused charlie.

There was a fire evacuation chute beside the window, a big doughnut of composite on thick swivel pinions. Ivanov grabbed Louise and hurried her along. He pulled the release lever at the side of the chute, shoving it through a hundred and eighty degrees. The window fell out, an alarm sounded, and water rained down out of the ceiling sprinklers all along the corridor. The doughnut swung round to lock into place in front of the open window. A fabric stocking concertinaed out, the pressure it had been stored under making it pour outwards like a liquid. It fluttered away from the side of the tower as it kept on expanding, the free end sinking towards the black ground far below.