A Moscow subway tunnel, built in 1935, is starting to fail. One tunnel night crawler, Sergeitch (Sergey Sosnowski), sees a leak in the tunnel where it runs under the Moscow River and informs the assistant station master (Michael Fateev), who mocks the old man for worrying about it, saying it's only groundwater. Meanwhile, Irina Garina (Svetlana Hodchenkova) is torn between her lover, businessman Vlad Konstantinov (Anatoly Bely), and her husband, surgeon Andrei Garin (Sergei Puskepalis). Konstantinov tries to persuade Irina to divorce Andrei. Arriving from a trip abroad, Irina spends the night with Konstantinov rather than going home. Andrei has to take their daughter Ksenya (Anfisa Wistinghausen) to school but by chance, they take the "Garden" metro station. Simultaneously, Konstantinov arrives, hurrying to work and forced to park his car because of traffic jams. Meanwhile Sergeitch, drinking with casual acquaintance Galina (Elena Panova) next to the "Garden", recalls that the water leaking into the tunnel smelled of slime, which means that it can not be groundwater. They are detained by the police for drinking alcohol in a public place but Galina manages to escape, and flees into the subway. In custody Sergeitch asks for a phone to tell the dispatcher everything, but the police turn a deaf ear to his pleas.