Günther has invited Paul to his family's house outside Berlin and Paul has accepted, hoping to see Günther's sister Hilde again. Paul has met Hilde once before and she's made quite an impression on him. Hilde is a free spirit who believes that it's OK for a woman to have several lovers at once but she's never looked at Paul that way. She is much more fascinated with Hans a boy from a much lower class who works in the kitchen of a restaurant/dance club that she and Günther frequent. Problem is Günther is also in love with Hans.
Add to this somewhat incestuous, somewhat quadrangular love arrangement, the Leopold and Loeb philosophy of the day, throw in a weekend party of heavy drinking and absinthe use, top the whole thing off with a pistol that Günther has become fascinated with and you have a recipe for disaster.
The movie opens with Paul being interrogated after two of the party goers end up dead, so you know that this isn't going to be a happy story from the very start but watching these attractive young people as they meander through the events that lead up to this tragedy is fascinating.
This movie unfolds slowly and will not be to everyone's taste but there are images and moments that will linger with the patient viewer long after seeing the film. I especially like the way that Günther's homosexuality played a part in the story but didn't dominate it.. It was just one aspect of the overall course of events and was treated as just another fact of these people's lives.