The bureau is interested in how the Fly Team operates, specifically in one agent. In FBI: InternationalSeason 4, Episode 12, “Blood Doesn’t Become Water,” a new agent joins a manhunt for an American couple who are on the run after a murder. The Fly Team welcomes Special Agent Riley Quinn (Veronica St. Clair), who joins their ranks in a particularly challenging case that takes them to Syria. Special Agent Quinn is also on a secret mission investigating a team member. A sneak peek of the February 18 episode reveals that she is investigating Supervisory Special Agent Wesley Mitchell (Jesse Lee Soffer), the Fly Team’s new leader. The logline below previews the episode’s case, while the sneak peek shows Quinn’s not-so-secret attempts to dig up dirt on Wes.