Air traffic controller Johann Lenders has just taken over the night shift in the tower at Zurich Airport when he notices an irregularity on the radar screen: two planes on a collision course. His efforts to avert the impending collision fail. A Russian passenger plane and a German cargo plane collide, killing 71 people. Meanwhile, Yuri Balkayev waits at Barcelona airport for his wife and two children to arrive - in vain. His family are among the victims of the Überlingen accident. Unable to comprehend the news of his loss, he sets off in search of those responsible. Johann Lenders is also completely distraught, he can hardly believe the disaster. He feels compelled to apologize to the relatives of the victims - but Katharina Rohl, a lawyer at air traffic control, forbids him to do so on behalf of the company boss.