Seven and Janeway play hologames. Seven is a poor loser.
It's five months since they got the encrypted Star Fleet transmission and they still haven't been able to decode it. It probably just contains recipies and so on anyway. Ha! Janeway just made the same joke.
Neelix and Tom return to Voyager with supplies and an alien who helped them in their negotiations by translating. His race has a natural ability to translate. He helps Janeway crack the transmission and they set out to co-ordinates in the message where they find a Star Fleet vessel, the USS Dauntless. Which appears to be powered by a Dalek time controller(Tom says it's a Quantum slipstream drive). The Dauntless pisses off, taking Chakotay, Tom and Tuvok with it.
2 days later, Voyager and the Dauntless meet up again. They discuss using the ship to get home and/or modifying Voyager for slipstream. Janeway is paranoid re the convenience of the whole thing.
Seven points out to Torres that when she gets back she may be put on trial for being in the marqui. Kim finds something unusual in the Dauntless engine room. Seven tells Janeway she doesn't want to go to Earth with the others. Janeway mentions it's 9 months since Scorpion...
Janeway decodes the last part of the message to discover Star Fleet didn't send the Dauntless, the first message was fake. Tuvok and Kim, meanwhile, have found alien technology in Engineering on the Dauntless. Janeway confronts the alien, who blames Seven. The alien takes off with the ship, Janeway and Seven.
The alien tells Janeway that her helping of the Borg to defeat Species 8472 was detrimental to his species. The Borg assimilated his species, and now he's taking them to be assimilated too. Tsk, there's no pleasing some people.
Voyager gets Quantum slipstream working and makes after the Dauntless. Janeway and Seven set about escaping MacGyver style and knock the ship off course. Voyager turns up and knocks out the Dauntless' shields, then beams Janeway and Seven off the ship. The Dauntless ends up in Borg space while Voyager nips off for home. Unfortunately the ship only lasts an hour at slipstream and they have to return to warp.
Seven and Janeway play their holosport again, and Seven says she's working on a way to have Quantum slipdtream without damaging Voyager. Teh end.
And so endith season 4.