In the third-season episode "End Run", he returns, having dispatched his pursuers by a particularly clever ruse. He poses as an investor in the latest business venture of Michael's younger brother Nate. Brennen tells Michael he will have Nate killed if Michael does not agree to help him. Although Michael gains access to the device, he bluffs Brennen into believing that he has drained Brennen's offshore accounts and sent a hitman to kill his daughter. Brennen releases Nate and leaves empty-handed, swearing vengeance.
