In near-future England, Caitlin visits her mother, Maureen. As Maureen gardens, Caitlin tells her that she will be on the radio that day, and confirms what she’s spent her whole career as an astrophysicist investigating: in a few months, an event called the Big Rip will occur, and will tear apart all of the atoms in the universe and destroy all life. Maureen suspected that this would occur, so her reaction is calm. She asks Caitlin about the fifteen contacts they’ve received from extraterrestrial civilizations, but Caitlin doesn’t comment. Four months before the catastrophe, Caitlin visits her mother again. Despite the announcement, things have gone back to normal, albeit with some resource shortages. Caitlin tells Maureen that she might agree to go on a submarine on the day of the Big Rip, just so that she’ll get to survive the event for thirty minutes more than the rest of humanity and observe its consequences. Maureen is supportive of her daughter’s plans. On the day of the apocalypse, instead of going on the submarine, Caitlin goes to her mother’s house. Caitlin’s husband and kids had just taken pills administered by the government that would end their lives before the event happened. As their atoms split, Maureen asks her daughter what the aliens said when they contacted Earth. Caitlin says that they said goodbye.