Early in his life, an unknown foe invaded Barash's homeworld and his mother brought him to hide on the planet Alpha Onias III. He was left with an advanced holographic environment generator, equipped with neural scanners which could create scenarios from his own thoughts. However, this proved poor substitute for real companionship.
In the year 2367, the Federation starship USS Enterprise-D visited Alpha Onias III. Barash prevented the away team leader, Commander William Riker, from beaming back to the ship, and created a holographic scenario in which Riker had lost sixteen years of memories. In those sixteen years, Riker had been promoted to captain of the Enterprise, married, and become father to a son, Jean-Luc Riker, a role Barash himself adopted. Riker eventually realized the scenario, and "Jean-Luc", were not as they appeared, and Barash finally admitted his deception. Learning the young alien's story and motivations, Riker offered to take Barash off Alpha Onias and back to the Federation, an offer Barash accepted. (TNG episode: "Future Imperfect")
During his time aboard the Enterprise, Barash befriended much of the senior staff, including Captain Jean-Luc Picard and Dr. Beverly Crusher, as well as Wesley Crusher, who taught Barash to play parrises squares. Shortly after, Barash was brought to Starbase 718, and the offices of the Federation Displaced Persons Agency.
During the month he spent there, Barash was cared for by the Andorian zhen in charge of the DPA office. He also tried to assist the base commander, Admiral Sternberg and her crew, in determining his origins, but they were unable to do so, concluding his people had likely originated from somewhere in Romulan space.
He later was relocated to Earth, and a youth community home in Ho Chi Minh City. There he became a mentor to younger children, and as an adult took on a formal role within the DPA, helping in the refugee crises following the establishment of the Demilitarized Zone, and during the Federation-Klingon War of 2372-2373 and the Dominion War.
Following the Borg Invasion of 2381, Barash, now a Director in the Paris office of the DPA, recruited Dr. Crusher to lead a fact-finding mission to a refugee camp on the planet Pacifica. Other team members he recruited were sociologist Meron Byxthar, civil rights attorney Paul Dillingham, and Starfleet engineer Thur chim Gliv. Unfortunately, Barash was unable, once Crusher reported back, to send any immediate additional assistance. (TNG novel: Losing the Peace)