Paris is demoted and sent to the brig.
Tom Paris is demoted to ensign and sent to the brig for thirty days, and while serving his time he records a letter to his father explaining how it happened. Voyager had met the Moneans, who live on a planet made of water held together by a containment field, and the Delta Flyer took Paris and Monean scientist Riga to the planet's core.
They found that the Moneans' oxygen mining is causing the water world to lose mass and that it could be gone within a few years. When Burkus, a Monean official, shows little interest in fixing it, Paris and Riga steal the Flyer to destroy one of the mining plants, but Voyager stops them. Janeway punishes Paris for disobeying orders. At the end Tuvok frees him, and Paris sends the letter. The fifth-season episode is an environmental story that also explores Paris's difficult relationship with his father, Admiral Owen Paris.