The Q who would be later known as Quinn was discovered by the USS Voyager in the Delta Quadrant, imprisoned within a comet for over 300 years. In the year 2372, he was released from his confinement accidentally by the Voyager crew. His escape immediately drew the attention of the Q Continuum who sent their representative Q (who had previously pestered the USS Enterprise-D in Star Trek: The Next Generation and was portrayed by John de Lancie) to place him back in confinement.
Captain Kathryn Janeway attempted to bring an end to the Q's stalemate, questioning Quinn as to why he was imprisoned. Quinn explained that he wished to die and Q argued that he was mentally unbalanced, going on to say that Quinn's suicide would bring chaos to the Q Continuum. It was then decided that there would be a hearing to determine whether or not Quinn should be granted asylum aboard Voyager, a hearing which Quinn, represented by Tuvok, would ultimately win. Quinn attempted to prove his life was pointless and caused him unendurable boredom. He did this by taking Janeway to the Q Continuum, which was presented in the Human-comprehensible form of a house in the middle of a desert with a road running by it. The road, he told her, represented the universe's edge and there was nothing left for him to explore. None of the Q in the Continuum spoke anymore, because all things had been discussed and all things were known. Quinn told Janeway that his life's work was complete and that he had done everything there was possible to do, yet was forced by his people to continue to live. Captain Janeway ruled in favor of Quinn, despite Q's attempted bribe of whisking Voyager back to Earth. Reluctantly keeping his word, Q turned Quinn into a Human, with mortality, after the verdict.
Janeway tried to convince Quinn not to commit suicide, since he now had a whole new mortal life to experience. As a Human, Quinn briefly served as a crewman aboard Voyager. Janeway and Chakotay wondered whether he should be assigned to stellar cartography, noting that they might as well shut down that department given Quinn's vast knowledge. Knowing he would never truly fit in as a mortal, Quinn nevertheless committed suicide with a sample of Nogatch hemlock procured by Q, who was inspired by Quinn's "rebelliousness".