Magnum, P.I. (1980)

First in a two-part story. Tyler McKinney, an old commando acquaintance, asks Thomas, Rick and T.C. to help him rescue a buddy who is held prisoner after being captured in Chong Ker, Cambodia. The three have no reason to like or trust McKinney after he involved them in a dubious mission in Vietnam, but individually they all eventually agree to help him on the mission. They head off to Cambodia, with the unexpected accompaniment of Higgins, but the mission has dangerous consequences in store for Rick...