Professor Thomson (the accountant of Henry Plonk, the most powerful weapons dealer in the world) has fallen into the hands of the German Border Police and the German Secret Service is hoping to get inside information from him about Plonk and his organisation. A Secret Service officer named Lehmann gives Charly and Rubelli the job of picking up the professor with their AK1 and flying him along a particular route to his interrogation in Berlin.
The two of them soon realise, however, that "Lehmann" has lured them into a trap: In the forests near Berlin a fighter jet attacks them and commands them to land. But Charly outmanoeuvres him and Rubelli gets rid of him permanently with one shot from the impulse cannon. Shortly thereafter, they are able to hand the professor alive and well to the real Lehmann.
In the meantime, Dahlberg has discovered that the whole scam looked very much like the work of a mercenary named Marcos who is wanted all over the world. Plonk is obviously prepared to do anything to get Professor Thomson back. Meanwhile, in a hotel room, Thomson and Lehmann are engaged in a bitter tug of war. Thomson has a photographic memory and is willing to talk, but in exchange he wants a whole new identity---something that Lehmann refuses to do.
Disguised as waiter, Marcos and his men sneak into the hotel. They murder Lehmann and the policemen in cold blood and then kidnap Thomson. Charly knows that Thomson doesn't have a chance and that Plonk has to kill him. Luckily, however, Charly had given the professor a watch which beams out the location of the person wearing it. Just as Thomson is about to be shot, the AK1 team shows up and whisks him away. Marcos pursues them in a fighter jet but thanks to a special new rocket (one of Thorwald's little inventions) they are able to defend themselves successfully.