Harlan looked toward the long bank of elevators at the back of the lobby. Two of them were on the upper floors; the third was descending. He looked back at the boy.
"What is your mother's name?"
"Vanessa Brooks, sir."
"Frank," Harlan said without turning his head, "do you have eyes on Vanessa Brooks from the cleaning service? She works the 38th floor."
Frank was already speaking into a handset. He listened, said something low, and listened again. He looked up at Harlan.
"She clocked in at 6:52, sir. She has not clocked out, but the supervisor for that floor says she stepped away from her cart about twenty minutes ago to take a phone call and has not come back."
Harlan's mouth went dry in a way he had not felt in many years. "Pull the cameras," he said quietly. "38th floor, every angle, now."
Frank nodded and turned to a second monitor.
Harlan looked down at Isaiah. The boy had not moved. He was standing very still, his hands still gripping the strap of his backpack, his small face composed in the way that small faces sometimes compose themselves when there is more fear inside than the face can comfortably hold.
"Isaiah," Harlan said gently, "your mother is going to be all right. I am going to make sure of it. But I need you to stay right here with Frank until I come back. Will you do that?"
The boy nodded.
Harlan stood up slowly, picked up his portfolio, and walked behind the security desk. Frank had brought up four screens. The 38th floor was divided into a long central corridor, two glass-walled office suites, a small break room, and a service hallway that ran behind the elevators toward a freight lift the cleaning staff used to move their carts between floors. The cameras showed all of it: the corridor was empty, the office suites were empty, the break room was empty, the service hallway was empty.