Neelix returns to Voyager from a diplomatic assignment with a guest alien by the name of Arturis. In spite of language difficulties between the two races involved in the diplomacy, Arturis has impressed Neelix by resolving the dispute without any prior knowledge of the languages of either of them. When presented to Janeway, Arturis informs her that his race have exceptional linguistic aptitude, and that he himself knows over 4,000 languages. Arturis is highly magnanimous about his abilities, saying that it's only in his species' nature, and that other species possess great strength, whilst humans possess a great generosity of spirit.
Seven of Nine's reaction to Arturis is somewhat less favorable. We learn that his species is known to the Borg as Species 116, and that the Borg has been unable to assimilate the species, or at least not yet. Arturis describes the Borg as a force of nature, similar to a violent storm. One does not feel anger or hatred toward a storm, therefore he does not feel anger or hatred toward the Borg.
Janeway in the meantime has been having great difficulty deciphering a message received from the Alpha Quadrant. Even with the help of Seven of Nine and her Borg algorithms, the data appears to be too heavily corrupted due to the distance it has travelled. It suddenly occurs to Janeway that Arturis may be able to help, as his skill with verbal languages may also extend to computer programming languages. Indeed, he is successful in reconstructing the message, apart from one section of data that is beyond repair. The message contains details of new Starfleet engine designs using quantum slipstream technology, as well as nearby spatial coordinates where they will be able to collect a new ship using the new technology and return home to the Alpha Quadrant within three months.
Voyager arrives at the coordinates and discovers a highly advanced Starfleet vessel named the USS Dauntless (NX-01-A). It is unlike any Starfleet vessel previously designed. The message from the Alpha Quadrant indicated that as well as vastly superior engine design, the ship would also have everything required by the crew for their relatively short journey home. A small away team transports over to the Dauntless to examine the ship further. Without any interference, the engines of the ship power up on their own, sending the ship 15 light years away within a minute, much to the amazement of the crew. It becomes apparent that the new ship can cover the distance to Earth within 3 months.
The crew are inspired by their new hope, but Janeway has her reservations. Her instinct is telling her that the entire set of circumstances is too good to be true, and that something is amiss. In her words; "They even turned down the beds. All that was missing were chocolates on the pillows." The crew nevertheless continue to examine the new technology and attempt to modify Voyager's engines to use the new slipstream technology. Unfortunately, Voyager 's hull is not designed to withstand the stress of travelling at such high velocity, so the prospect of merely modifying Voyager to make the trip back by itself using these methods is unworkable.
Meanwhile, Seven of Nine expresses her concerns at not being able to adapt to life on Earth among billions of humans, and informs Janeway that she does not wish to return to the Alpha Quadrant with the rest of the crew. Janeway points out to her that she has a choice between travelling to Earth or returning to the Borg Collective. Seven insists that she will survive on her own in the Delta Quadrant using her Borg perfection.
Janeway and Tuvok reach the conclusion that everything is far too perfect, to the point where it is beyond reasonable coincidence, and that Arturis has somehow been deceiving them since his arrival on board the ship. She decides to reexamine the transmission received from the Alpha Quadrant, and discovers that the data described by Arturis as beyond repair is in fact the original message, and that the previous message was fake, fabricated completely by Arturis, including the coordinates where they are to collect the Dauntless.
At the same time, Ensign Kim discovers alien technology behind a panel on board the Dauntless and alerts Tuvok. Janeway decides that it is time to challenge Arturis over his motives and identity. His initial response is to deny everything and to blame Seven of Nine, saying that it was she who fabricated the false message from Starfleet, and that there is bound to be evidence in her data logs to this effect. Janeway instantly dismisses this notion, saying that any evidence was put there by Arturis in case he was caught. With many of the Voyager crew on board the Dauntless, Arturis rips a panel from the control console to expose a lever which he pulls, sending the Dauntless into a quantum slipstream. The remaining crew on board Voyager manage to transport most of the crew back in time, except for Janeway and Seven of Nine. It turns out that the Dauntless was never anything more than Arturis' alien ship, camouflaged as a Starfleet vessel using highly advanced technology.
Chakotay orders Tom Paris to activate the slipstream technology on board Voyager in order to pursue, even though it has not yet been tested. Arturis reveals his motives and intentions behind his deception of the Voyager crew. It turns out that his homeworld was recently attacked by the Borg and incorporated into Borg space, and all but a few hundred of his species were assimilated. This is contrary to Seven of Nine's earlier statement, indicating that the attack happened since she was severed from the collective and therefore had no knowledge of it. Arturis blames Janeway and her crew because of her previous alliance with the Borg (see "Scorpion"). Arturis' species had a vested interest in the Borg war with Species 8472 and believed that had the Borg been destroyed then their homeworld would still be free. All he has left to live for is revenge against Janeway, and resolves to bring her and as many of her crew as possible to the Borg for assimilation, even if it means that he too will be assimilated.
Imprisoned within a forcefield by Arturis, Janeway and Seven formulate a plan to escape. Borg drones have the capability to walk through most forcefields due to their electromagnetic shielding. Seven of Nine still has this ability, though her Borg implants require a few simple modifications. Once this is done, they escape easily and challenge Arturis to stop what he is doing and keep the spirit and identity of his species alive in himself, in a similar way to the El Aurians as mentioned by Guinan (see "The Best of Both Worlds"). Arturis fails to see reason and destroys the ship's navigational controls, sealing the fate of all three of them.
Voyager appears just in time to disable Dauntless' shields and transport Seven and the Captain to safety. Having destroyed his own controls, Arturis is unable to alter his course and ends up exactly where he had planned, in Borg space, but ironically he is alone, and is the sole victim of his own plan. He is greeted by several Borg cubes and is presumably assimilated.
The new technology gained by Voyager lasts only a short time, but still provides them with enough velocity to shave 300 light years from the remainder of their journey.