"I wish you were here". Constable Robert Lanz from Hamburg again receives a postcard with these words written on it, this time from London. Lanz knows, it is the provocative comment of a brutal tourist killer. "The Tourist", a mass murderer who goes on a killing spree when on vacation, has hit again. Once again the victim, his thirteenth, was a women. Lanz has been tracking the murderer for years, but his legwork has been in vain so far. Lanz leaves for England immediately and it seems as though this time he is successful. During a hunt over the roofs of London, the suspect dies. The case seems to be closed. But Lanz faces a new problem, his wife Karen feels neglected. To save his marriage they go off to Vienna. There, a cat and mouse game starts, this time with the police officer as the mouse. The murderer wants to destroy him by going after the officer's unsuspecting wife.