The fourth season opened with an hour-long episode, where viewers were told that Trapper John had received his orders to go home and Mike Farrell made his first appearance as BJ Hunnicutt. The season also saw Harry Morgan arrive as Colonel Potter, replacing Henry Blake as the commanding officer. Other highlights included a bombardier believing he was Jesus Christ, Major Burns discovering that his wife wanted a divorce, and Hawkeye reuniting with his ex-girlfriend (Blythe Danner).
The 4077th is under pressure with an artillery barrage moving closer, patients going downhill in the bitter weather, and Frank desperately ransacking Houlihan's tent to recover his love letters. Comedy, starring Alan Alda, Mike Farrell, Larry Linville and Gary Burghoff.