“I’d like to know what this man Reis has done,” Gideon murmured.

“Well, think it over, Dr. Chase. You have a Ph.D., don’t you? Some private college in Massachusetts?”

Gideon nodded.

“There you are. It would be easy. A professorship at Harvard or Princeton could be readily arranged. It would involve very little actual work and would convey a great deal of prestige.”

“What has Reis done?” Gideon spoke to the president, not to John.

“He’s a spy,” the president said, “an’ that’s just for starters. We can’t nab him ’cause we got no evidence. But he travels around. He stops at sensitive spots. He don’t stay long, but soon afterward our sources in—well, never you mind. In a certain foreign country, okay? They tell us certain people there have got holt of somethin’ we were tryin’ to hold close to our vests.”

Gideon shrugged. “Have him killed.”

“Not ’til we find out how he does it.”

John said, “He’s found a flaw in a security system we thought just about flawless—not something he can exploit now and then, but something he can exploit whenever he chooses. We’ve got to know what it is.”

“That he can exploit,” Gideon murmured, “only when he is in close proximity to the facility in which your secret operations are being carried out.”

“He’s a blackmailer, too,” the president said. “We know that.”

“For money?” Gideon’s gaze roved the room.

“Sometimes.” John cleared his throat. “More often for other things. Sexual favors, at times. Introductions and information.”

Gideon said, “You will have considered that he may be blackmailing someone at each of the industrial plants and laboratories he visits. They are plants or laboratories? Most of them? May I assume that?”

“He would have to meet with them, or telephone them at least,” John said.

Gideon looked amused. “E-mail them? Write letters? What about carrier pigeons?”