The federal agent had a daring pitch for Nicolás Maduro’s chief pilot: All he had to do was surreptitiously divert the Venezuelan president’s plane to a place where U.S. authorities could nab the strongman. In exchange, the agent told the pilot in a clandestine meeting, the aviator would be made a very rich man. The conversation was tense, and the pilot left noncommittal, though he provided the agent, Edwin Lopez, with his cell number — a sign he might be interested in helping the U.S. government.