But once again, the business of anthrax would be conducted under this roof. He glanced up. The windows were all dark. He was to meet the seller on the fourth floor.

Reaching the side door, he swiped the lock with an electronic keycard supplied by his contact at the base. He carried the second half of the man’s payment over his shoulder, having wired the first half a month before. Gray also bore a foot-long plastic, carbonized dagger in a concealed wrist sheath.

His only weapon.

He couldn’t risk bringing anything else through the security gate.

Gray closed the door and crossed to the stairwell on the right. The only light on the stairs came from the red EXIT sign. He reached to his motorcycle helmet and toggled on the night-vision mode. The world brightened in tones of green and silver. He mounted the stairs and climbed quickly to the fourth floor.

At the top, he pushed through the landing’s door.

He had no idea where he was supposed to meet his contact. Only that he was to await the man’s signal. He paused for a breath at the door, surveying the space before him. He didn’t like it.

The stairwell opened at the corner of the building. One corridor stretched straight ahead; the other ran to the left. Frosted glass office doors lined the inner walls; windows slitted the other. He proceeded directly ahead at a slow pace, alert for any sign of movement.

A flood of light swept through one of the windows, washing over him.

Dazzled through his night-vision, he rolled against one wall, back into darkness. Had he been spotted? The sweep of light pierced the other windows, one after the other, passing down the hall ahead of him.