2.3 The Changeling

Stardate: 3541.9

Plot Summary
The USS Enterprise, answering a distress call from the Malurian star system arrives to discover all life in the system, including the Federation science team that preceded them, has been wiped out.

The Enterprise is then ambushed by a vessel firing an energy bolt which reduces the shields to 20%. They return fire, but the vessel merely absorbs the full blast of the photon torpedo. After taking more hits from the vessel, Kirk hails the assailant. The vessel ceases fire and opens communication in binary. It turns out to be no more than a meter long, and allows itself to be beamed aboard the ship.

The object identifies itself as a space probe named NOMAD, and refers to Captain Kirk as "the Creator". First Officer Spock discovers that the NOMAD space probe was launched from Earth in the early 21st Century on an exploratory mission although when questioned, NOMAD maintains that its mission is to "find and sterilize imperfection". As biological life forms are believed to be imperfect, it 'sterilizes' them by extermination.

NOMAD mistakes Captain Kirk for Dr. Jackson Roykirk, the scientist who created it. Kirk plays upon this mistake to issue orders to NOMAD.

NOMAD slips past its guards to investigate the sound of Lt. Uhura singing. When she is unable to explain singing to NOMAD, it probes her mind, and finding it to be chaotic, erases her memory. Mr. Scott tries to stop NOMAD, and is killed by the device, but is brought back to life by NOMAD when it learns that 'The Creator' (Kirk) wishes it, and NOMAD has been given access to human physiology and medical data by Bones. Meanwhile, Uhura is sent to Nurse Chapel to be reeducated.

NOMAD is placed in a holding cell for further study. Spock attempts a Vulcan mind meld with the device. From the meld, Spock learns that NOMAD survived a collision and eventually encountered another, alien probe called Tan Ru, which was created to obtain and sterilize soil samples from planets, possibly as a prelude to colonization. The two probes integrated with each other resulting in a machine with a hybrid of the programming of both machines in a new paradigm: explore and "sterilize imperfections", armed with Tan Ru's formidable weaponry.

NOMAD wanders to the the Enterprise engine room where it eliminates inefficiency in the ship's engines causing the ship to move at warp speeds beyond the Enterprise's structural capacity. Kirk arrives just in time to order NOMAD to reverse the changes.

Kirk realizes that NOMAD, having seen the Enterprise's star charts, will eventually find its way back to Earth and exterminate all life there. He tells it that its sterilization of biological units is illogical, since The Creator is a biological unit. Kirk orders a security team to take NOMAD back to the holding cell, but it kills the guards and goes to sickbay where it examines Kirk's medical records. NOMAD then turns off all the life support systems of the Enterprise, in order to destroy the imperfect units that "infest" it.

Kirk confronts NOMAD a second time, questioning the logic of destroying imperfect beings. Kirk tells NOMAD that it has made a mistake, and is therefore imperfect as well. He tells NOMAD that he is not 'The Creator', he is Captain James Kirk, not Jackson Roykirk, and NOMAD's failure to discover its first error is a second error. Kirk says that NOMAD's failure to exterminate itself is yet another error. NOMAD follows Kirk's logic and pursuant to its primary functions, destroys itself. Kirk orders two gravity devices placed on either side of NOMAD, and the probe then beamed into space. There it explodes.

Production Notes
This episode is believed to have been inspired by the episode of 'The Outer Limits', called "The Probe".

This episode was the inspiration for the TV series 'The Questor Tapes'.

This episode is believed to be the inspiration for Star Trek: The Motion Picture.