The corpse of a girl in a ballet costume is found in a lake high in the mountains. Nearby, the police find a page from the book "Brothers Lionheart" and a camera, in the lens of which the number "4" is scratched. It soon turns out that the ballerina was killed by a shot of antifreeze in the heart. Holger Munch's team gets down to business. Even Mia Kruger is delaying her much-needed vacation to help Holger solve this terrible crime. Soon another corpse is discovered: a young jazz player lies on the bed of a cheap hostel, music plays, and on the wall there is an inscription - a quote from the cartoon "Bambi": "Look what I can do." In the lens of a nearby camera, you can see the number "7."