Plot summary

A group of criminals serving death sentences are sent on a mission in space to extract alternative energy from a black hole. Each prisoner is treated as a guinea pig by Dr. Dibs (Binoche), who is fixated on creating a child through artificial insemination, but has yet to find success. Sexual activity between prisoners is prohibited. The ship is equipped with "The Box," a device obsessively used by the crew to masturbate. Dibs murdered her own children and husband before attempting suicide. Monte (Pattinson), the only celibate prisoner, rejects Dibs' sexual advances. Monte is serving a life sentence for killing a friend for murdering his dog as a child. Monte's only friend on the ship is Tcherny (Benjamin), who is drawn to the onboard garden because it reminds him of Earth.Pregnant prisoner Elektra (Obianyo) delivers a baby, but it dies, and later she does as well. The captain, Chandra (Eidinger), develops leukemia due to radiation and has a stroke before being euthanized by Dibs. One night, male prisoner Ettore (Mitchell) binds a female prisoner named Boyse (Goth) and her roommate Mink (Tran) to their beds and attempts to rape Boyse. Nansen (Buzek), the pilot, intervenes, but Ettore attacks and overpowers her. Monte arrives, throws Ettore off Boyse, and beats him. When Monte leads Boyse away to be treated, Mink stabs Ettore to death in the hallway. Dibs begins doubling the amount of sedatives each prisoner receives, later sneaking into Monte's cell and raping him while he is sedated. She then injects his semen into Boyse, who produces a healthy child that Dibs dotes on, but Monte is unaware that he is the baby's father.As the ship approaches the black hole, Nansen prepares to pilot a shuttle around it. Unbeknownst to the other prisoners, Boyse kills Nansen with a shovel and takes her place. The shuttle travels through a molecular cloud that alters its trajectory and causes it to dive into the black hole, where Boyse explodes due to spaghettification. Mink later attacks Dibs and injures her, but is then killed by Monte. Dibs informs Monte that the child is his before ejecting herself into space. Tcherny commits suicide and Monte buries him in the garden according to his wishes. Now the only surviving prisoner, Monte removes the bodies from the ship's morgue, dresses them in spacesuits, and releases them into space.Monte struggles to raise the baby, whom he has named Willow. He attempts to make repairs to the ship, but her frantic cries through his helmet speakers causes him to drop a tool and lose it in space. Much later, when Willow has grown into a teenager, they encounter another ship similar to their own. Monte boards the ship, but finds it carrying stray dogs who have survived by eating one another. Willow begs Monte to bring one back, but he refuses, implying contamination could potentially sicken or kill them. The ship moves closer to the black hole, and Willow convinces Monte to board a shuttle with her and journey through it. Monte takes Willow's hand as a yellow light source grows ever larger and envelops them.