Logan realized that his feet had taken him all the way to the end of the central first-floor corridor. Ahead, two wooden doors blocked his way. Before them was a velvet rope, hanging from brass stanchions and holding a large sign, which contained the symbol of a hard hat and the message CONSTRUCTION AREA. AUTHORIZED PERSONNEL ONLY.

Logan had signed a long series of documents for Dr. Olafson absolving Lux of any obligation or responsibility in the case of personal injury, and he had carte blanche to roam the entire campus. Glancing over his shoulder and finding the wide corridor behind to be empty, he stepped past the velvet rope, pulled a key from his pocket, unlocked the doors, and stepped inside. It was very dark, and the air smelled of sawdust and joint compound. Closing the doors and fumbling in his duffel, Logan pulled out a flashlight, snapped it into life, and swiveled it around. Locating a bank of light switches, he flicked them on, one after another.

He found himself in a small vestibule, apparently a kind of front office for the entrance to the West Wing. The furnishings were all covered with protective drapes, and the wooden floors were hidden beneath multiple layers of drop cloths. They gave the space a strange, anonymous feel. There was only one exit — a large, doorless arch directly to the south — and after finishing his reconnoiter Logan moved through it.

He paused a moment to put down his duffel and page through the working blueprints and reports he had brought with him. Based on the construction schedule, the first job would — naturally enough — be the demo. One team of workmen had been tasked with demolishing the fixtures in preparation for a full-scale rebuilding. A second team of workmen had been given the rather more delicate job of tearing down certain non-load-bearing walls on the second floor to make way for what had been termed in the architectural specs “lateral corridor A” and “lateral corridor B” — the two new hallways off which the redesigned office and lab spaces would be constructed. The rest would follow later.

Stepping into the space beyond the vestibule, Logan found himself in darkness once again, the only light being that which filtered in from the front office. He looked around, found another bank of lights, and turned on the switches. Nothing: clearly, the electricity had been turned off for the purposes of demolition. Switching the flashlight back on, he found he was standing in a seemingly roofless space. There were additional drop cloths on the floor, but here they had been wadded and twisted this way and that by the passage of numerous booted feet, and Logan could see the heavy dust that lay on the floorboards beneath. On all sides, ancient stones rose up around him: Delaveaux’s ceremonial henge. Hemmed in by walls, the liths seemed even larger than they actually were. Logan let his flashlight shine on them, angling its beam up toward the ceiling far above. They were rough-hewn, dark, tapering slightly toward their top edges. What events, good or ill, had they witnessed? Had they seen Richard III die in the nearby battle that marked the fall of the Plantagenets? Or older ceremonies, profane and dark? There was something about these silent sentinels that Logan found unsettling, and he was careful not to touch them as he moved on.

Beyond the standing stones, a corridor led deeper into the wing. Logan moved down it until he reached a staircase, which he ascended. The second floor was a confused jumble of half-destroyed offices. Bare lights dangled from cords. The dust was heavier here, but it was primarily plaster dust, caused no doubt by the wholesale demolition of walls and nonstructural elements to make way for Strachey’s two parallel hallways. Standing where he was, Logan could make out the rough outlines of what must be lateral corridor A. It was visible, not so much from what had been built but from what had been torn away: a long, gaping hole, ripped out of offices and storage rooms and corridors, heading due south into the dark.

With the aid of his flashlight and a compass, Logan consulted the work orders for the construction. The demo work for lateral corridor A was to come first, to be followed later by corridor B.

He moved ahead slowly down the unfinished corridor, swinging the flashlight left and right. He was uncomfortably aware that he was in a construction zone; some of the half-destroyed walls and slanting ceiling beams were clearly less than stable. Not only was he without a hard hat, but he was investigating a space that had just been declared structurally unsound.

He continued south for perhaps twenty yards, peering around with his flashlight, before his way was blocked by two tarps hanging from the ceiling to the floor, one blocking his way ahead and the other to the right. They had been nailed into place, and a hastily scrawled sign was fixed to the closest that read: HAZARDOUS AREA — OFF-LIMITS.

He paused in the dust-heavy darkness, considering. Then, pulling a penknife from his pocket, he cut a small hole in the tarp ahead of him, thrust his light into it, and peered through.

Clearly, this was where the demolition work had stopped. Beyond lay rooms that, though dusty and long abandoned, had not yet been touched. What was it about this spot that had suddenly convinced Strachey the wing was unsound?

Lying on the floor in front of the tarp wall was a small gold mine of equipment: nail guns, sledgehammers, compressors, a portable generator. It was almost as if the workers had dropped their tools and run.

He hesitated a moment. Then, turning, he shone his light over the tarp that blocked his way to the right. Once again, he took a penknife to it, then peered through the tear that resulted. To his surprise, there was no opening or corridor beyond — but instead a bare wall.

This was odd. Logan could understand why Strachey would bar entrance to an area that might be unsafe. But why cover a wall?

Carefully, he pulled the tarp away from the nails that fixed it in place and pinned it back, exposing the wall beyond. It was clearly old, dating back to the original construction of the West Wing. Workmen had removed some of the wallpaper and plaster, exposing the old laths.

In the middle of the wall, at approximately chest level, a ragged circle of plaster, roughly the size of a fist — or the head of a sledgehammer — had been set into the lath, like a plug in a dike. Logan examined it with his flashlight, then scratched at it with his fingernail. It was fresh plaster, only recently set. It could not have been applied more than a few days previously.

Using the tip of his knife, Logan worked away at the edges of the plaster patch, easing it away from the surrounding matrix of lath until it fell out, landing at his feet. Where it had been was now a hole in the wall, black against black.

Bending forward, Logan shone his flashlight at the hole and peered into the cavity beyond. Almost immediately, he went rigid.

“What the hell?” he muttered under his breath.

He snatched the flashlight away, almost as if he’d been burned. Then he stepped back: one step, another.

For a long time he stood, staring at the ragged circle of black. And then — laying his flashlight on the ground so that it illuminated the wall — he pulled a sledgehammer from the pile of equipment. Hefting it, he tapped it gently against the wall a few times. Then, taking a firmer grip on the handle, he struck the sledgehammer against the lath surrounding the hole.

A spiderweb of cracks appeared, and a rain of plaster chips fell to the ground.

Again and again, Logan hammered at the wall, but cautiously, calculatingly, knocking away the old construction, creating a passage just large enough to duck through.

After about ten minutes of work, he’d extended the space from the preexisting hole down to the level of the floor: a black maw about four feet high and two feet wide. He put the sledgehammer down and wiped his hands on his sleeves. He paused a moment in the darkness, listening. He’d been as quiet as he could, but a sledgehammer was not a delicate instrument. Nevertheless, there was no sound of voices, no calls or cries — this far from the occupied areas of Lux, his work had gone unnoticed.