Ulla Strömstedt

On a tourist trip abroad the passengers on the coach witness an assassination attempt on the President Hurkas. One of the tourists has evidence against the perpetrators, and is killed when the coach reaches Sweden. Another passenger observes how one of the perpetrators is picked up by a yellow car. She is kidnapped and locked up in a mental hospital.

Passengers in an american tourist travelling in a country which is not named, witnesses a murder attempt on the country's heads of state, Prime minister Hurkas. On the trip are: John Hillman, as a tourist, a doctor, Björk, who happens to film the event, and his daughter Kerstin. In addition, a person, as it turns out, the evidence against the bombers. He was killed when the bus reaches Sweden. The offender escaping. Kerstin follow and see how he picked up in a yellow car. Kerstin is now a dangerous witness for the men in the yellow car. They try to run over her. When this fails, she is instead kidnapped and taken to a mental hospital. Hillman gives chase and manages to save her. Traces of the yellow car that leads to Stockholm.