The crew of the Reliant were kept on a strictly need-to-know basis about Project Genesis. They were given enough info to do their jobs with safety, but nothing more than that.
Khan questioned Terrell only briefly, but it seemed to give him great pleasure to extract information from Chekov. By the time he finished, he knew each tiny detail of what precious little anyone on Reliant had been told about the classified Project Genesis. He knew where they had been, he knew where they were going, and he knew they reported to Dr. Carol Marcus.
When he interrogated Chekov, he learned that Kirk would have access to the full Project Genesis files.
With an edge in his voice, Khan asked, "Could he find out about it?"
Kirk was a member of the Fleet General Staff; he had access to any classified information he cared to look up. Chekov tried desperately to keep that knowledge from Khan Singh. His mind was working so fast and well that he knew, without any doubt, what Khan planned. He knew it and he feared it.
"Answer me, Mr. Chekov."
"Yes."
