The cave people convene with Boss (Cliff Norton) about items that have gone missing. He feels it all started when the stranded astronauts Mac (Frank Aletter) and Hector (Jack Mullaney) arrived. Boss tells them that if anything else goes missing he will kill them (the 11th time in 18 episodes they are met with this fate). They return to their cave to find someone is trying to frame them with the stolen items. With the help of Gronk (Joe E. Ross) and Shad (Imogene Coca) they secretly put the items back with their owners in the middle of the night. However, the next morning they are met with accusations of more stolen items. Boss and Clon (Mike Mazurki) search the cave and find the newest stolen items, leaving the astronauts little choice but to flea. They're captured by Clon and summoned to Boss, but when the evidence disappears, he has little choice but to free them. Mac concocts some fingerprint powder and finds a thumbprint that's not thiers on the rock by Hector's bed where the items were planted. Gronk and Shad go around to the cave people in the village with a cup for them to touch and get a thumbprint from. When Hector messes them up, Mac devises a burglar alarm at the entrance to their cave. Their trap catches the surprising thief with an almost touching conclusion.
This is not a very funny episode, but there is enough plot and suspense to hold one's attention throughout.
Creator Sherwood Schwartz saw the repetition of plots and as a result this is the final full episode in prehistoric times. He pulled a 180 with the series and sent some of the cave people with the astronauts to modern day (1960s) for the final eight episodes.
