“The hot-desks are over there.” He pointed to the area behind reception, near the managers’ glass cubicles and the break-out room.

“I guess they moved them. I was given this one ages ago. Maybe they did it by mistake,” Richard offered.

“What you need it for anyway?”

“I kept some tax forms and things here for safe-keeping while I was away in Moscow.”

Callan paused again, preparing to escalate the level of confrontation. But this time he seemed to realise it was none of his business anyway. He relaxed slightly, perhaps to catch Richard off-guard.

“How was Moscow?”

“Expensive. Painfully expensive. The per diems barely covered our food. We were all teetotallers by the time we were done.”

Callan allowed himself a little smile at this. All the consultants drank like fishes when they were away from home. “I mean how did the project go?”

“Not bad. The project’s still ongoing but they’re into phase three now. I’m back in the UK for a bit.”

“What’s next for you?”

“Nothing next as yet. I’m still at Oldhams, for a good while.”

“Did you know that project will be finishing up soon?”

“No?” Richard’s heart missed a beat. If he was moved on from Oldhams, what was the point in having the memory stick?

“Be careful.” Callan looked pointedly at him. Richard felt an involuntary spasm in his cheek. He wasn’t very good at this, he realised.

“There are a few redundancies coming up. Consultants need to be chargeable.”

“Don’t worry, I know that.”

With that, Callan decided to withdraw. Richard watched him move slowly and purposefully back up the corridor and re-enter his frosted glass cubicle. Callan was another of those on-contract project managers that rarely made an appearance in the office and seemed to have the vaguest workload. For some reason, Richard didn’t like him. He waited until he was sure Callan was settled into his cubicle before quickly picking up the envelope. Then he went down the service elevator at the back of the building to avoid having to pass Callan’s office.

Christ! If I’m made redundant, the plan’s over, he thought.

People swarmed towards Richard and bustled past. Most of the swarm was heading south, as he was, pouring out of the City, streaming across London Bridge and disappearing into the station named after it. But some of the most agitated and determined ones were, for some reason, going against the flow.

A seagull swept through the air, holding its wings out rigidly to be carried by the wind. Richard imagined what the seagull, looking down, would think of the human folly it observed.

And suddenly Richard too was high above it all, looking down on himself and seeing his stupid mistake with chilling clarity.

He was trapped. He could see the bridge spanning the Thames from north to south and the river itself beneath, running west to east. He could see himself, by now halfway across, being carried along with the flow of humanity – just another anonymous member of the multitude on the left-hand pavement, busily progressing to the South Bank. To his right, traffic flowed freely in each direction, and on the far right-hand side other members of the agitated nest bustled past each other.

His attention focussed on the person he knew to be himself. He could see through this person’s coat and into the pocket where the memory stick was clutched in his fist.

What if someone accidentally jostled him? What if a pickpocket decided that he was an easy target?

What if the members of the swarm, still blandly unaware of his intentions, somehow sensed the threat to their hive and turned on him?

He would lose a memory stick that was worth around a fiver, but was irreplaceable. He would lose his chance to change the course of history.

He saw the melee developing. From above he watched the swarm converging on him. Then, looking through his own eyes, faces full of fury. But that was from a future which, although it was foreseen, had not yet happened.

And then he felt a twinge of guilt. These were people, not members of a hive or nest. These were the very people he intended to destroy. Wealthy bankers, City workers, spoilt middle-class Londoners with pleasant jobs that all relied on financial services.

In his guilt he realised they would be justified in turning on him. It wasn’t likely; nevertheless he tried to think of a way of escape. But of course, there was no way of escape. He began to realise he was no more trapped here on the bridge than anywhere else. He would be vulnerable wherever he went. He just had to get home as soon as possible.

All he had to do was get himself, his laptop bag containing both envelopes, and the memory stick in his pocket, back home. But it wasn’t easy when every passer-by might somehow realise you were a ticking time bomb.

And then a surge of rage boiled up within him. It wasn’t easy when you gave in to feelings of guilt. He gripped the memory stick until he felt it would cut into his hand. These were the very people on whom guilt or pity was wasted. They had to be destroyed for the good of humanity.