Elisa Sherlyn and her family live in a modest apartment in Colonia Roma, a neighborhood in Mexico City that sits on the edge of affluence and struggle. They are sliding into a deep financial crisis, with the looming threat that they could lose their car, their furniture, and even their home if debts pile up. Their situation grows tenser after her father reveals a stark, almost apocalyptic idea: when the world is about to end, humanity might have to subsist on cockroaches. This unsettling thought sets a grim tone for what follows.
Elisa tells this to Miguel Imanol, her younger neighbor and friend, and together they start collecting cockroaches in a plastic box, turning a macabre omen into a growing preoccupation around their shared roof-top adventures. One day, they meet Paco Rubén Rojo Aura, a punk kid who sneaks onto their rooftop to raid a neighboring building for chickens, drawing Elisa and Miguel into a more troubling world than they imagined.
A visit from Gómez, a bank employee, makes the family’s precarious finances even clearer: if her father cannot pay his debt, they could lose not only the car but also the furniture and even the apartment itself. To raise money, Elisa’s parents sell the television and a gun her father once owned, hoping to buy some time. Elisa decides to look for a job to help the family weather the crisis. Paco hints that he has access to something from his brother that could help them earn money, nudging Elisa toward making riskier choices.
The next day, Paco shows Elisa a gun his brother used for robberies, but the weapon has no bullets. Elisa contemplates robbing a store to pull in cash; however, after another visit from Gómez, she shifts her plan and targets the bank itself, deciding to seize the moment while the opportunity presents itself. As a test of nerve, Elisa and Paco visit a toy store and threaten an employee to steal two pairs of roller skates, a bold move that exposes how far they’re willing to go.
Elisa updates Paco about the toy-store theft, but he confesses that the gun had no bullets, since he could not obtain any ammunition. She then remembers that the bullets might still be somewhere in the house and sets out to find them, eventually discovering them hidden in her parents’ closet. The day of the planned robbery arrives: Elisa meets Gómez outside the bank as he starts his day, while Miguel and Paco wait across the street, each of them braced for what could unfold.
They enter together, with Elisa joining the queue and prepared to use the weapon. Before she can act, an armed group storms the bank, firing as they declare a robbery. Outside, Paco attempts to enter the bank but is shot dead by an accomplice. Inside, Elisa is caught in the crossfire and dies as the chaos erupts around her.
The final scene unfolds on the rooftop: Miguel stands with a dead cockroach from Elisa’s collection, placing it carefully on the edge of the fence as he mourns the loss of his two friends and gazes out over the city they once inhabited with hopeful, fragile dreams.
