The Enterprise comes across a space probe as they go to establish contact with the reclusive Melkotians. The probe warns the Enterprise to immediately leave Melkot space. Kirk tries to contact the Melkotians, but there is no response and they continue with their orders. When they reach Melkot, Kirk takes down a landing party and they face death penalties for not heeding the Melkotian's earlier warning. The telepathic Melkotians draw on Kirk's memories for the manner of their execution... and come up with the Showdown at the O.K. Corral.