Mike and Zoe arrive in Mexico, masquerading as surfing honeymooners in an undercover mission to thwart a plot to smuggle terrorist weapons into the U.S. Sarah and Billy are also on the case---but surprising developments jeopardize the assignment.

Mike poses as a marine to thwart a rogue military officer's explosive scheme to blow up a dam. Helping him in the mission: a beautiful undercover agent. Elsewhere, Billy is tutored in the fine art of combat.