Eddie Paskey

Dr. Leonard "Bones" McCoy meets a former girlfriend when the Enterprise brings supplies to a remote archaeological survey group. Still attractive to McCoy, the woman's current appearance and her colleague hide a deadly secret, ultimately revealed as a tragedy of ecology.

While exploring the energy barrier at galaxy's edge that crippled an earlier ship, Kirk's long-time friend and crewmate Gary Mitchell begins mutating into a god-like entity disdainful of the "mortals" around him. Can the captain overcome his own feelings for his friend before the new entity grows too powerful to stop?

An alien virus picked up from the now-dead Psi 2000 outpost strips the crew of their inhibitions, causing chaos as each individual is overcome by hidden emotions -- even Spock. Meanwhile, the disabled crew have left the Enterprise unable to react to the planet break-up below that is pulling them down.

A machine that destroys planets threatens the Enterprise.

A magnetic ore brought back from Alfa 177 causes a beam break-up in the transporter, splitting Captain Kirk into two different beings: one "good" and one "evil." The malfunction must be repaired before Sulu's stranded landing party freezes to death -- and Kirk's separated "halves" perish.