Mia and Nico decide to leave Spain due to a crisis that has caused a shortage of basic necessities and a tyrannical government. They fear for their lives and the safety of their unborn child. The couple had previously lost their firstborn daughter, Uma, who was taken away by the military and is presumed dead. Mia blames herself for Uma’s disappearance and carries the guilt with her.
Nico’s plan is for them to escape to Ireland by being transported on a cargo ship. However, they get separated, Nico is loaded onto another container, and Mia faces challenges on her own. She manages to hide during a military checkpoint where everyone else on her truck is killed by the police. Mia tries to contact Nico to warn him of the danger but fails to reach him.
Mia’s cargo is eventually loaded onto a ship, but a storm causes the containers to fall into the ocean. Her container, slowly filling with water, has a cargo of tupperware, earphones, flatscreen TV’s, vodka, and hoodies, all of which she uses to help herself survive, along with a drill, some tape and a penknife she had managed to salvage from earlier. Upon hearing screams she looks out through a bullethole and sees another container full of people a few metres away sink beneath the surface. After two days inside the container, Nico calls her and tells her he is on the way to rescue her
That night, Mia gives birth during a storm to a daughter, Noa. Mia becomes determined to ensure her baby’s survival, despite being severely weakened, having delusions of Uma, and even resorting to eating her own placenta. As the water level inside the container continues to rise, Mia manages to puncture a hole in the roof using drill and the penknife, and she and Noa climb on top of it. She manages to catch fish using a makeshift net. Whilst trying to capture the attention of a passing aeroplane, Mia severely gashes her leg. She stitches it using parts from the TV’s and uses the vodka to sterilise the wound.
After approximately 20 days, Nico calls Mia and reveals that he has been shot by the military and is unlikely to survive. Mia is devastated but shares the news of their daughter’s birth with Nico in their final conversation. Nico urges Mia to continue fighting and reach Ireland, promising to always be with them in spirit.
Mia constructs a makeshift raft using materials from the container and drifts in the ocean after the container sinks, hoping for a miracle. Eventually, she is discovered by a family on a fishing boat who find Noa floating on the raft. Mia, however, is unconscious and tied to the raft with a rope. They bring her on board their boat and perform CPR, successfully reviving her.
Mia and Noa are rescued and brought to the shores of Ireland.