The Rat Patrol (1966) : 1x11

Moffitt and Tully allow themselves to be captured so that they can get information from Craig -- an American POW -- about Rommel's new battle plans. However, Marston, another POW, tells them that Craig died. Dr. Phillips -- the camp medic -- supposedly has some information about the plan, though. When the medic treats Moffitt's arm he puts the code name of the mission on the underside of the bandage : Operation Nachtigall. However, it soon becomes obvious that either Phillips or Marston is a traitor and it is up to the Patrol to figure out which, as they are both now giving the Patrol conflicting information.