Time Thieves - Dean Kootz

"Mr. Mullion," one of the triplets said, looming up twenty feet away as Pete followed the smooth railing. He stopped, his heart racing, but he felt a break in the rail as he did so. He edged forward a foot or two and felt around with his boot until he discovered a step. In a moment, blood pounding in his temples, he was halfway down toward the lower level, taking two risers at a time, no matter what the danger of a fall. He heard the mechanical man start after him as he set foot on the cement floor.