SEASON 6, EPISODE 608 - While tracking down a felon running a heroin ring inside a prison, Agent Ian Edgerton becomes a murder suspect when the informant he meets with ends up dead, sending a desperate Edgerton over the edge when he takes a member of Don's team hostage. Lou Diamond Phillips ("La Bamba," "Stargate Universe") Returns as Agent Ian Edgerton. Guest Stars Include Christopher McDonald ("Happy Gilmore," "Family Law") as U.S. Marshal Frank Thompson and Missi Pyle ("Heroes") as U.S. Marshal Janet Galvin, Who Are Both Involved in the Edgerton Investigation.