Rony (Filip Blazek), the owner of a travel agency specializing in extreme sports, receives an interesting request - a trip down the dangerous Black River. The client who initiated the expedition has, it seems, a very serious reason for wanting to go to this remote area, where a Czech water sport enthusiast once died under mysterious circumstances. For Sasa (Jirí Langmajer), the mystery of the distant family tragedy is almost forgotten. Now the chance to learn the truth has come. But the other members of the expedition have no inkling of the real aim of the trip. In the days that follow, they will have to not only reach to the very depths of their physical strength, but also to discover what words such as courage, fair play, friendship, and love mean to them, and to come to terms with the truth, no matter what it is.