Thomas Riker

Thomas Riker was an exact clone of William T. Riker, who was created following a transporter accident in 2361. As time progressed from the point of the accident, the two Rikers developed different personalities based on their differing life experiences.

Nervala IV
In 2361, the USS Potemkin was ordered to evacuate a Federation research base located on Nervala IV. The planet was notorious for its atmospheric distortion field which prevented the use of transporters or shuttlecraft, except for brief periods every eight years. On arrival in orbit, Lieutenant Riker was ordered to lead the evacuation teams down to the surface and ensure that all personnel was evacuated.

Once all of the personnel had been beamed aboard the Potemkin, Riker requested to be transported aboard, however difficulties with the transport led to the operator creating a second annular confinement beam to help with the transport, and with the intention of merging the beams once Riker was safely stored in the pattern buffer. However, due to the unusual atmospheric distortions only one beam reached the Potemkin, and the other rebounded to the planet's surface, and unbekownst to the Potemkin 's crew, created a second Riker.

Riker lived alone on Nervala for eight years, believing that one day he would be rescued, not knowing that another Riker was carrying on his life. However, he was eventually discovered in 2369 when the USS Enterprise-D arrived to check on the research base again. Leading the Enterprise away teams was Will Riker, and despite some problems between the two Rikers' they worked together to ensure that the Enterprise was able to download the base's computer files. (TNG episode: "Second Chances").

Following his rescue from Nervala IV, Riker took the middle name of Thomas and made that his first name. With assistance from Captain Jean-Luc Picard, Tom decided to continue his Starfleet career and was offered a position aboard the USS Gandhi, under the command of Captain Azon Lexen. (TNG episode: "Second Chances", and novel: Double Helix: Quarantine).

The Maquis
In 2371, the Gandhi was assigned to patrol the Demilitarized Zone and Captain Lexen ordered that Riker take a shuttlecraft and proceed to Outpost Sierra III so that medical supplies could be brought aboard ship. On the return trip to the Gandhi, Riker is intercepted by the Maquis and taken to Helena, a planet made up of differing cultures, that is experiencing a plague similar to the one that struck Archaria III and Bajor. Torn between his duty to Starfleet and helping the Maquis, he decides to join the Maquis and uses the medical supplies to help treat the citizens of Helena. (TNG novel: Double Helix: Quarantine).

Several months later, Riker travelled to Deep Space 9 and posed as Commander Riker as a ploy to capture the USS Defiant. After managing to get a guided tour of the Defiant by Major Kira Nerys, Riker engineered a build-up to a warp core breach which would allow them to take the Defiant out.

After collecting some Maquis crewmembers, Riker took the Defiant into Cardassian space and headed for the Orias system where he had heard rumors that the Cardassians were massing a large fleet. Despite entering the system, the Defiant was forced to withdraw when faced with a large fleet of Keldon-class warships. Unfortunately, these warships were not under the control of Central Command, but the Obsidian Order.

Thankfully, Commander Benjamin Sisko and Gul Skrain Dukat were able to engineer an agreement that would return the Defiant, Major Kira and the Maquis crewmembers to the Federation, while Riker would remain a prisoner of the Cardassians, with the sensor data from the Orias system being handed over to Dukat. (DS9 episode: "Defiant").

Lazon II
After a brief show trial on Cardassia Prime, Riker was able to escape the death penalty but was sentenced to life imprisonment in the labor camp on Lazon II. Life on Lazon II was brutal for all imprisoned their, and the main work was the mining of deutronium ore. However, Riker was able to befriend a Romulan prisoner, by the name of Saket.

A few months later, it was revealed that Saket was a Romulan agent who was working for Commander Sela. Sela was able to use a Peregrine-class fighter to breach the defenses of the labor camp and extracted both Saket and Riker and get them to safety. (TNG novel: Triangle: Imzadi II).