Ziegenthals (Jürgen Prochnow), a failed student, makes ends meet as an academic ghost writer. By accident he discovers that the respected professor of sociology, Rüdiger Kolczyk (Klaus Schwarzkopf), has plagiarized his doctoral dissertation by translating the work of an American scholar. He decides to blackmail Kolczyk and to ask for 10,000 DM and additional monthly payments of 1,500 DM. Kolczyk initially agrees, but vows to Ziegenhals that "only one of us will survive". Looking for a way to fight back, Kolczyk tries to gather information about Ziegenhals from Miezi (Elke Sommer), a prostitute and a housemate and friend of Ziegenhals. As Miezi has saved enough money she is thinking of leaving her profession. At the same time her violent ex-boyfriend and former pimp, Kalle Prötzel (Claus Theo Gärtner), has been released from prison; he murders her and steals her savings. During the investigations the police find out that Miezi had an appointment with Kolczyk and discovers the payments Kolczyk makes to Ziegenhals. Being the main suspects in the murder investigation only increases the hatred between Kolczyk and Ziegenhals, who fight with all means available. Kolczyk, learning that Ziegenhals thinks that Kolczyk wants to kill him, starts playing with Ziegenhals' mind. For example, he sends him a package with an alarm clock, making Ziegenhals think that he has received a mail bomb. Ziegenhals meanwhile befriends Kolczyk's daughter Ginny (Kristina Nel) and makes her his lover. Although this forces them both to have to pretend in public that they are friends, the final disaster cannot be averted.
One or the Other of Us was Petersen's first theatrical feature film. Petersen had already directed several high-profile films for television, including four episodes for the Tatort television series. Klaus Schwarzkopf and Jürgen Prochnow had already played in some of Petersen's Tatort productions. The script was based on the novel of the same name written by Horst Bosetzky, a professor of sociology. At this time the identity of Horst Bosetzky was unknown as due to his position as a professor he published under the pseudonym -ky.[1]One or the Other of Us was shot in October and November 1973 in Berlin and Sylt. The film was shot in Eastmancolor on 35 mm in a 1.66:1 aspect ratio.[2]
The film made its theatrical debut on 22 February 1974 at the Gloria-Palast in Berlin. It was first aired on television on 12 February 1982 on ZDF. The film was released on VHS in 1998 and on DVD in 2008 in Germany.[2]
