Special Guest Stars A.J. Buckley as Adam Ross Guest Stars Robert Joy as Dr. Sid Hammerback Mykelti Williamson as Chief Brigham Sinclair Kerr Smith as Drew Bedford Frank Grillo as Jimmie Davis Erin Daniels as Det. Brennan Co Starring Walker Curry as Young Mac Taylor Garrett Ryan as Young Andrew Davis Bryan Becker as Bobby Toole Dave Marlin as Young Jimmie Davis Eddie Driscoll as Hal Weston Houston Luke Hooker as Young Will Davis