A cryonic exploration vessel from a hundred years ago approaches Babylon 5, bringing with it a deadly creature and a human from the past. A lunatic named Amis (Dwight Schultz) begins making grand assertions of doom; when Garibaldi investigates his past, he discovers that Amis was a decorated combat veteran. Garibaldi takes an interest in Amis, and asks him to explain his story. Amis explains that when his unit was attacking a remote enemy base, they came across a ghostlike alien that began feeding on his men.
Z'ha'dum is mentioned as being a possible destination for the creature that attacked the station. A stylized depiction of the creature is also shown to be in the Book of G'Quan at the end of the episode.