When the last train of the night blows through the station and disappears deep into the tunnel system beneath Moscow rather than stopping and releasing its passengers, and when authorities successfully stifle all talk of the disappeared train and passengers, it falls to a group of young people to work their way into the tunnel system to try and discover what has happened to their friends. And while I have no idea if they succeed in finding what they went in looking for, they certainly find something.
Production values on the Tikhon Kornev film look absolutely first rate. Take a look at the trailer below.