Harry Kim wakes up in 24th-century San Francisco and no one seems surprised to see him there — not his girlfriend Libby, nor a local coffee shop owner named Cosimo, nor his friend Lieutenant Lasca, a fellow design specialist at Starfleet Headquarters. As the strange morning continues, Kim finds himself in an important meeting with high-ranking officers who want to hear Kim and Lasca's proposal for a new runabout.
Feigning illness, Kim leaves the meeting and tries to figure out how he got to Earth. A check of Starfleet records reveals that he never served on Voyager, which, as Kim well knows, has been reported missing in the Badlands. He also finds out that Paris isn't on the crew manifest; he's been paroled from the penal settlement that Janeway found him at and now lives in Marseilles. Kim heads to France, seeking answers only Paris can provide.
He locates his friend at the real Sandrine's, but to Kim's chagrin, Paris doesn't know him. Still, Paris is intrigued by Kim's story. His last recollection is being in a shuttlecraft heading back to Voyager, and Kim begs Paris to accompany him to Starfleet Headquarters where they can run a computer simulation and learn what happened to him; Paris refuses. When Kim arrives home, he is apprehended by Lasca who suspects he may be a Maquis spy. Until the matter can be settled, an electronic anklet is place on Kim to monitor his whereabouts.
Later, Cosimo tells a distraught Kim that he was sent to keep watch over him after Kim's shuttlecraft intersected one of his species' "time-streams." The incident scrambled Kim's time-line and sent him back to the life he would have known if he hadn't joined Voyager's crew. In an effort to help Kim, Cosimo tells him where to find the time-stream that could take him back. Kim says goodbye to Libby and makes a run for it, only to be apprehended by a Starfleet security guard. Thankfully, Paris arrives on the scene and helps Kim out. The pair then flee.
Needing a ship to recreate his shuttle accident and ride the time-stream back to Voyager, Kim boards a runabout at Starfleet Headquarters. With Paris at the helm, he recreates the conditions of the incident that sent him to Earth. Suddenly, he finds himself back on his original shuttlecraft. Kim is beamed onto Voyager, where he resumes his normal life.