During a visit to a planet, Captain Kathryn Janeway and Chakotay are bitten by an insect borne virus and they are doomed to die. The only thing that will keep the two alive is something in the environment of the planet that they had visited. Doctor suggested contacting the Vidiian but Janeway doesn't want that to happen.
After six weeks without the captain, Voyager comes across a Vidiian colony and Harry Kim suggest a plan but Tuvok declines to implement the plan. Kes manages to persuade Tuvox to change his mind. Voyager contacts the Viidians and they get put through to Denara Pel, the Viidian who the Doctor had help in Lifesigns. She says she has a cure and arranges for the cure to be transported to the Voyager in exchange for Klingon blood which is resistant to the Phage virus.
Voyager is betrayed by the Viidians but Tuvox was expecting that and manages to manoeuvre Voyager to safety. Voyager returns to the planet where they left the captain and give them the cure. Chakotay and the Captain return to the ship and return to the journey in hand.