STORY LINE (in english):
'The vehicle tuning specialist and former racing driver Robert Geffken sneaks into the house of the machine manufacturer Zangemeister with a gun and is surprised by his housekeeper Ms.. Naumann. When she tries to overpower him, she is shot by him.  He is waiting for Zangemeister in Zangemeister's house and demands 450,000 DM from him or he will murder his family after some explanation.  Zangemeister still calls the police, but Geffken has bugged him and briefly returns to the house.  As a warning, he shoots him in the foot.

Police senior commissioner Heinz Haferkamp goes to Zangemeister's work to interview the engineer Mr. Schassler, among others in Zangemeister's factory, who looks around out of the windows that day like he's expecting visitors for some reason.  

During questioning from Haferkamp, Schassler is open about not having a good relationship with his boss.  In the hospital, Zangemeister reports to the inspector that he and Mr. Schassler had been wrestling with compensation for an invention in the same amount as the burglar and blackmailer asked.  Haferkamp later visits Schassler at home and meets his daughter Ellen, who has kept a stiff leg after a daring jump' out of 'the window.  After the unsuccessful conversation with her father, Haferkamp and his police assistant Willy Kreutzer see her with her unusual limp immediately leave the house and get into a yellow car.  They cautiously follow her to Geffken's workshop.

Ellen accuses Geffken of carrying out her father's plan to blackmail Zangemeister.  Geffken admits this, but says he is only doing it for her father so that he does not lose his job. Ellen doesn't believe him, especially since the amount of money asked makes her father look suspicious to the police. She drives off.

Haferkamp gets out of the car and goes in to speak with Geffken, while Kreutzer follows Ellen.  While Geffkin is being questioned, he lights a cigarette and appears to guzzle hard alcohol from the bottle without offering any.  

Schassler himself goes to Geffken. "You are an international racing star without a penny of money?" asks Mr. Schassler.  He also asks if Geffkin demanded a half million Deutschmarks from Zangemeister.  Geffkin answers: "That could be so".  'Schassler tries to influence Geffken and is starting to feel that he has to find another way to do this. The way that he planned and carried it out is not diverting enough suspicion from Schassler, himself.

Geffken goes to the place where the money was handed over.  He is followed by Haferkamp after an all night stake out. Initially, Geffken shake them off because of his faster car.  

Geffken sends Mrs. Zangemeister through several siops in Essen with the extortion money, but he notices that Haferkamp and his colleagues are monitoring the handover.  He demands that commissioner Haferkamp withdraw his men and not pursue them any further, otherwise he will kill one of Zangemeister's nephews.  At a deserted crossroads in the country' outside of Essen, 'Mrs. Zangemeister finally leaves the money with the blackmailer.

Meanwhile, Ellen Schassler has come up with a plan to put a stop to the hated Geffken and his blackmail.  She studied guns and gets a hold of a pistol. She has a book to explain how guns work.  She examines the weapon carefully enough to manipulate the firing pin so that it won't work properly.  Her father walks in and sees this going on.

She then goes to Haferkamp's apartment and explains that she wants to meet Geffken at a cemetery that she shows Haferkamp the next day.  Ellen plans to confront Geffkin about the extortion there, but doesn't explain the part involving bringing the gun there to Geffken.  She lures Geffken to the cemetery on the pretext that she reported him to the police.  Haferkamp is watching them.  She gets Geffken to take the rigged weapon and threaten her because she is threatening him with her walking stick.  Geffken checks to see if the gun is loaded.  It is.  Ellen, then acts surprised, then continues to threaten to beat him daring him to shoot the gun.  When he tries to pull the trigger and it doesn't work, Haferkamp shoots him at close range.  Ellen's plan worked, but Haferkamp sees through it.  Unfortunately, he can't prove it to her.'

SOURCE: (updated)from Wikipedia Germany, Wikipedia the free encyclopedia
-- https://de.zxc.wiki/wiki/Tatort_(Fernsehreihe)#Liste_der_Tatort-Folgen
(see: 'Main article : List of crime scene episodes')
-- Book written by Werner Kließ