Clarke took out his keys, opening the door, turning on the lights and revealing a narrow staircase. He ushered Leo inside, locking the door behind them before descending the stairs. The air was dry, machine-processed. At the bottom of the stairs was a small drab office where Clarke turned off an alarm system. To the side of the office was a steel door, sealed shut, like a bank vault. After entering a code, there was a faint hiss as the door opened. Lights automatically turned on, fluorescent bulbs slowly flickering one after another in quick succession, revealing the archive’s full dimensions.

Far larger than Leo had expected, the archive stretched for hundreds of metres with row upon row of steel shelves. Unlike a library there were no books. Everything was stored in uniform brown cardboard boxes, side by side – thousands of them, each with the same gap between them. Leo looked at Clarke:

—All this?

Clarke nodded:

—Seventy years’ worth of material, most of it understood, some of it not.

Leo moved forward. Clarke put a hand on his shoulder.

—Before we start, there are a couple of rules. I’ve been instructed to search you upon leaving. Please don’t be insulted: this is standard policy and applies to all visitors. You must wear these gloves when touching anything. Other than that, you’re free to look at whatever you like. Except no fountain pens, or ink of any kind. You don’t have any pens on you?

Leo shook his head, taking off his jacket, hanging it in the office. Clarke noted:

—You might want to keep that with you. The chamber is cold, air-conditioned for preservation purposes.

Seventy years’ worth of refrigerated spy secrets, thousands of attempts to betray, deceive and murder, preserved as though they were mankind’s finest achievements.

The ceiling was not particularly high, but the room was remarkably wide, giving it surreal proportions, the shape of squashed shoebox. The entire archive was concrete, resulting in two colours dominating, the grey concrete and the brown cardboard boxes. There was the hum of air and occasionally slight vibrations from a passing subway train. A passage ran through the middle of the archive from end to end. Each aisle was marked with a number. There were no signs, no written explanations. Clarke must have guessed his thoughts, remarkold/p>

—Don’t worry! We don’t want you to look through everything. I have put aside several boxes that I thought you might be able to shed some light upon. But you’re free to walk around and see if anything catches your eye. Why don’t you familiarize yourself with the archive before we sit down with the material I’ve selected?

Despite the suggestion that he was free to explore, Clarke had not left his side.