When Frank's longtime friend and informant is killed by Yakuza assassins, his quest for revenge puts him and Kyle at odds with an FBI agent whose operation against the Yakuza is jeopardized by Frank's actions.

An investigation into weapons trafficking becomes personal for Tommy when an old friend becomes connected to the case. Also, Lockhart demands to see results from Kyle's investigation into Frank's actions, leading Frank to reveal surprising information to his trainee.