Friendship One, which appears to be some sort of Voyager-type unmanned craft only with warp nacelles, ambles into the atmosphere of an alien planet while playing classical music at them.
On Voyager, Janeway is telling an Admiral about Distant Origin, but he says he's called up because of Friendship One. The crew have an exposition meeting - they're in the neighbourhood of where F1 was when it lost contact with Earth. They set about looking for the probe.
They locate the probe on a planet and cruise over to take a look. The planet is somewhat uninhabited because of the antimatter radiation. Tom and B'Elanna argue over whether she should go on the away mission - Tom wins.
The Flyer zooms down to the planet and is observed by a being in some sort of heavy protective suit. They find a music box toy which plays Vivaldi, and then find missile silos, and a lab in which the probe is housed. then they're captures by a bunch-o-people in protective gear. Chakotay and Kim are attacked when they return to the Flyer, and are forced to take off when the ship comes under attack.
The leader of the beings, Varren, contacts Voyager and says he's got the rest of the away team, and wants Janeway to find them a new planet to live on, or else.
In sick bay, HolDoc wakes up the fellow they retrieved from the surface. He explains that there was a containment failure in their anti-matter power grid, which started the nuclear winter. The probe was what originally gave them the tech to use anti-matter, and the Federation is largely blamed for the planet's current state.
On the planet, Tom wants to treat Carrey's head wound, but they won't let him use a medpack. He tries to befriend the pregnant woman guarding them, without much luck.
Janeway and co examine their options, while HoloDoc and Seven set about treating the patient.
Tom and Neelix befriend a young girl and give her the music box they found earlier, but Varren freaks out. Heh. Neelix chats with Varren and says he can put in a good word with Janeway. He's still less than friendly.
Janeway phones Varren again and says it'll take years to relocate everyone, but says that they might be able to reverse the nuclear winter. Farren agrees to send up one of the prisoners in exchange for food and medicine, but Farren shoots Carrey on beamup, and Carrey turns up dead.
Seven discusses with the patient the fact that the probe resulting in the destruction of their world was unintentional, and suggests he take over as leader from Varren.
The pregnant woman starts with the labour, and Tom attempts to help. The baby comes out but isn't breathing however Tom and Neelix manage to save its life. Is that the same rubber baby prop they used for the Borg baby last season?
Tuvok is captured... but it's a trick, and the hostages are rescued - Tom brings the baby so it can get treatment.
Janeway says they're going to beam down food and supplies and leave. Tom and Neelix argue that they should try to fix the nuclear winter, and they check out the patient's theories on correcting the planet's environment.
Voyager launches the technobabble torpedos into the atmosphere. Varren believes it's an attack and prepares to launch the missiles which have lain idle since the disaster. The other people rebel against him long enough for Voyager to complete its task, and the planet's atmosphere is restored.
Aaaaaand so Voyager continues on its way, after retrieving the probe, but Janeway and Chakotay look at Carrey's Voyager-in-a-bottle and mull over what's happened. Teh End.