FBI Agent Dennis Aderholt

Dennis Aderholt is an FBI counterintelligence agent working alongside Stan Beeman, methodical and sharp-eyed in a division built on suspicion. He's diligent rather than flashy, the kind of officer who reads a file twice and trusts the pattern over the hunch. Recruiting and running assets is his craft, and he takes it seriously.

Brandon J. Dirden plays him with a quiet, unshowy competence that makes him feel like the adult in rooms full of paranoia and improvisation. The show uses him as a mirror to Stan's messier instincts, and Dirden's restraint gives Aderholt an integrity that never tips into naivety — he's careful in a world designed to punish carelessness.