Whenever a criminal is killed in London, a black Jaguar is nearby, with a white cat always sitting in the passenger seat. Inspector Higgins and Inspector Lane find a joker card on all the victims. Their investigation leads them to a diamond smuggling ring.

Werner Blücher is what you'd call a real thoroughbred crook: not a second seems to go by without the cunning rascal coming up with an idea for the next coup. It's just too bad that Blücher's criminal career hasn't been too successful so far - his lawyer has just got him out of prison once again. And although his arch-enemy, the fanatical chief inspector Schmitz-Kesselhoff, is doing everything she can together with her dotty assistant Müller Zwo to get Blücher out of circulation once and for all, the gallant crook is already planning the next thing.

Tobias Totz is a very special zookeeper. He has a lot of understanding for his animals and everyone loves him, and he has grown very fond of the lion.