A subway tunnel between two Moscow stations has cracks due to construction problems. Water dripping from the tunnel ceiling has not attracted enough attention, resulting in the backflow of water from the Moscow River. The subway train carrying hundreds of passengers is trapped in the flood, which will not only cause the underground tunnel to collapse, but also destroy the entire city. Andrei Garin and his daughter, Dr. Xenia, are trapped in the tunnel. Dr. Garin tries to rescue the passengers, including his wife's lover. He must overcome resentment, anger and fear. In addition to survival, he must find his love and family.