He doesn't know what it is, but Captain William Clark can see that something terrible and strange is happening on the space station Meridian. Within a matter of minutes, three of the space stations crew - Commander Richard Gordon, Dr. Thomas Somerset and Commander Lara Nabakov - have been lured to their deaths by impossible visions of loved ones or enemies -- visions created by someone or something capable of reaching into the minds of human beings and recreating their darkest nightmares and fondest desires. Fearing for his safety and that of the one surviving crew member, Dr. Helene Dufour, Clark uses the escape pod and abandons ship. When he winds up on earth, however, nobody will believe his story. Instead, Clark is accused of committing the murders while suffering from space psychosis, and must turn to his ex-wife, Robyn Dysart to defend him. She manages to raise a reasonable doubt by suggesting that Soroxin, a chemical used in Somerset and Dufour's research, may have caused the sp