Two aliens are part of a band of "con artists" who believe that they've stumbled upon the greatest scam of their careers: Impersonating Janeway and her senior officers. Using their new Starfleet identities, they move from system to system engaging in a series of lucrative deceptions. Eventually, the real Janeway and her crew are blamed for these deceptions when the con artists do not deliver the goods as promised. Ultimately, the Voyager crew must bring the imposters to justice.
Neelix and Paris remember that they met two clerics named Dala and Mobar three weeks earlier while on shore leave. Apparently while Neelix and Paris weren't paying attention, Voyager's entire database was downloaded from the Delta Flyer. As a result, Dala and Mobar were able to obtain the information they wanted in order to pose as Federation officers.
In an attempt to track down the con artists, Janeway asks Orek, a Telsian who has been cheated by Dala and Mobar, for access to the scans of the imposters' vessel in order to derive their warp signature. Meanwhile, Paris and Neelix are frustrated with themselves for being duped so easily.
Back on the bridge, Tuvok detects a vessel whose warp signature matches the imposter's ship they are looking for. There's a larger vessel alongside the imposters which belongs to Varn, another angry alien who also was duped by the two con artists. Dala tells Varn that their "mothership" Voyager has arrived to defend them. Varn's ship begins firing at Voyager. The starship is successfully able to strike Varn's ships with its phasers, and knock out the tractor beam holding Dala's vessel.
Janeway instruct Seven of Nine to transport everyone on Dala's vessel to Voyager. However, because Voyager's transporters are damaged, Seven is only able to beam Dala onto the ship. Aboard Voyager, Dala refuses to reveal a detailed account of everyone they cheated, as well as the location of the stolen property. Janeway instructs Tuvok to hail Telsian Security and tell them that they have a prisoner to turn over (pulling a scam on Dala herself by relating how barbaric Telsian prisons are). In actuality, Janeway doesn't want Tuvok to call the Telsians just yet because she wants Dala to sit and think for awhile first.
Neelix visits Dala in the brig and engages in a heart-to-heart conversation with her regarding her options. However, when Neelix turns the other way, Dala knocks him to the ground and grabs the phaser from his belt. She takes off running down a corridor and stuns Tuvok with the phaser. She climbs inside the Delta Flyer and immediately escapes at warp speed.
Dala catches up with Mobar and Zar, a third con artist posing as Chakotay, and asks them to beam her aboard. In the meantime, Paris has been hiding in the Delta Flyer. He activates the mobile emitter and the Doctor shimmers in. Paris and the Doctor successfully capture Dala and the Doctor then turns into Dala in holographic disguise. He beams himself to the bridge of the imposters' vessel and cleverly manipulates Mobar and Zar into revealing the location of their stolen loot. Meanwhile, Voyager is waiting in the wings, and the two remaining con artists are apprehended.