In the 100th case facing Karin Reuter and her team in the Cologne police department they have to deal with a case of murder which stretches their investigative powers to the very limit. And it all looks like routine at first. When pensioner Helmut Behrens drops his wife outside a jeweller’s shop one morning, so she can have a ring altered, nobody could possibly imagine that Behrens will soon be a widower.
Shortly after Elke Behrens enters the shop a masked man bursts in, brandishing a gun and demanding that the staff hand over all the valuable watches. Although everybody hurries to do as he says, the robber is clearly extremely nervous. And when Elke Behrens makes a sudden movement, although not intending to threaten him, he is so startled that he fires his gun before fleeing with part of the loot. The elderly woman sinks to the floor, severely injured.
Helmut Behrens has been waiting a few streets away for his wife, and when she fails to turn up he comes back to the jeweller’s shop. She is just being taken to hospital. Behrens spends the next few hours hurrying between the hospital where his wife is struggling for her life and the police station, intent on finding the latest information about the robber. And it is at this point that our investigators begin to suspect the jeweller isn't as innocent as he pretends to be. There are certain indications that suggest he may have staged the robbery himself, since he is deeply in debt and could gain a considerable amount of money from the insurance. The behaviour of the robber himself, along with the mask he was wearing, suggest it may have been a criminal called Dieter Voss, who was only recently released from serving his latest stretch behind bars. Voss completely denies any involvement in the case. But there are several clues to suggest that the jeweller at least is not telling the truth about all this.
Our detectives now have the difficult task of breaking tragic news to Helmut Behrens: his wife has died from the trauma of the bullet wound. And a close examination of the video recording made by the surveillance cameras in the shop reveals that the robber forgot one small but crucial detail. But in the end it is another factor which leads to his downfall.
