The Hand of the Goral - S2.E11

Buck, Wilma, and Hawk explore a strange planet and come across the wreckage of a spacecraft and its lone survivor. He is taken back to the Searcher by Wilma, while Buck and Hawk continue to explore. After some unexplained happenings on the planet, they return to the Searcher, where they find that everyone has undergone personality changes -- becoming the opposite of their real selves. Buck soon learns that he can not even trust Wilma and Hawk to help him solve the mystery of what has happened.