STORY LINE (in english):
During a celebratory reception in a ministry in Vienna, the section chief Grahl is found dead in his office.  He was poisoned by a cup of coffee. Police senior inspector Marek and his police assistant inspector Wirz go to the ministry, where senior inspector Kramer, his colleague chief inspector Swoboda and ministry counselor Wiesiewicz are already conducting high profile questioning of the witnesses.  Police board member Gleiner pulls Kramer off the case because a state visit is pending, and Kramer is to take over the guarding of the state' visit.  'His colleagues Swoboda and senior inspector Gareis should continue the case, which would make Marek and Wirz superfluous.  

Wiesiewicz interrupts his own questioning of witnesses to reveal to Marek that it was he who asked not to entrust Marek with this case, as the case is very delicate and he also needs Marek for other tasks that are also related to the case.  The murdered section chief Grahl had recent concerns with foreign oil interests.  The police went through all the ministry's personnel files on the occasion of the murder and discovered that the wife of the section counselor Radler was under surveillance years ago because she was “well known” to a spy named Alfonse Dubois.  He now lives in Berlin, so Gleiner puts Marek on a search mission to Berlin to contact him, unobtrusively.
His colleague commissioner Kasulke greets him in Berlin or was it a fake Kasulke who was an imposter?  After speaking with Kasulke he sees Dubois, who lives in Berlin-Wilmersdorf and visits the Café des Westens along the Kurfürstendamm avenue every day.  There, Marek finally meets Dubois.  Dubois already knows about Marek's identity.  He asks Marek directly whether he is in Berlin because of the murder of section chief Grahl.  Dubois suggests that Grahl was also killed by one of his numerous lovers.  He claims to have stopped acting as an agent.  Dubois introduces his bride to Marek to demonstrate that he is now leading a civil life. Marek continues to ask him openly whether he has any more brides, which he affirms.  On board a double decker bus, he said he got to know the wife of the section counselor Radler because she had debts and he was a moneylender at the time.  That is how he would have met her husband and even the minister.  Coincidentally, files had disappeared from the ministry at the time and he was suspected.  That's why he went to Beirut.  Ms. Radler would have paid him back the money, including interest.  Dubois says goodbye to Marek because he is seeing his daughter..

Back in Vienna, Marek learns from Wirz that the chief inspector Swoboda has called in sick, so Greiner has now entrusted Marek with the case.  Wirz reports to Marek that the murder victim lived alone, was 58 years old and was the subject of stories of womanizing.  Ms. Zambusch, the secretary of section chief Ehmann, visits Marek and would like to add to her statement.  On the day of the death of section chief Grahl, shortly before the party, her boss Ehmann gave a package for section chief Grahl that contained a large sum of money that he had counted in front of her eyes. It was 100,000 schillings that he put in his desk drawer.  No money was found after the murder. However, she does not know what the reason for the payment was.  So, Marek asks section counselor Radler.  

Secretary Mantler had seen Radler go into section chief Grahl's office during the party and had heard from listening at the door that Radler wanted to borrow money from Grahl because of his financial worries.  Because Grahl would have refused him the money, Radler' insulted 'and threatened him.  Radler denies everything.  Marek confronts Radler' about how 'he had paid his debts to the bank shortly after the murder.  Radler refuses to say where he got the money.  

Senior commissioner Marek then 'visits Mrs. Wiesiewicz, Mrs. Radler and Mrs.. Ehmann, who have met to play cards together.  Marek asks Mrs. Radler about her financial difficulties, she admits that she is always in financial difficulties. Her husband would always straighten it out, including the debts her husband had repaid for her after the murder.  When asked about Mr. Dubois, she says that she has no relationship with him and that she never cheated on her husband. 

Ehmann meanwhile states that the 100,000 Schilling was the payment for a property purchase.  Mrs. Wiesiewicz says that Mrs. Radler has been away from the party for a while.  Marek asks Mrs. Wiesiewicz about the rat poison she bought for her garden.  It was the same thing Grahl was killed with, but she would have used it up in the garden.

The next day Mrs. Radler went to see Marek because she had received a letter from Dubois.  He makes hints and demands money.  In the letter he also mentions that Marek was with him in Berlin.  Mrs. Radler also doesn't want her husband to find out about Dubois' letter.  Marek copies the letter and sends it to Kasulke in Berlin so that he can take on the blackmail case.  Inspector Berntner mentions that one of the 1000 Schilling bills (a hundred note) appeared at a gas station, which has disappeared from Grahl's drawer.  The customer who paid with it was the secretary named Ms. Mantler.  

At that moment, Marek's boss Gleiner calls and informs Marek that counselor Radler was murdered in the ministry by the same poison as Grahl.  Marek delivers the bad news to Frau Radler, as it is still in his office.  Marek and his police assistant Wirz then go to the' Radler murder 'scene.  The poison worked very quickly, Radler fell straight from his desk to the floor.  Marek learns from section chief Ehmann that Radler would have succeeded Grahl, now ministry counselor Wiesiewicz will move up, in fact by two steps.  Ehmann notes that under normal circumstances, Wiesiewicz would probably not have had a chance to move up that high.  

Mrs. Wiesiewicz comes into their room and looks for her husband, who is not in his office.  Ehmann further reports that Radler and Wiesiewicz were with them today.  Nothing unusual struck him.  He had offered both of them cognac, Radler accepted, Wiesiewicz declined.  Radler was an alcoholic and Marek notes that the killer must have known this.  When Wirz read a review of a television game in which an officer became a murderer in order to be promoted, Marek realized that Wiesiewicz might be a suspect.

Marek and Wirz ask the secretary Mrs. Mantler where she got the money for refueling' at the gas station the day before. Wirz confronts them with the fact that the note comes from Grahl's drawer.  She denies this and says Grahl lent her 2,000 schillings because she was embarrassed.  Wirz and Marek confront her with the fact that someone staying with her tenant is a marriage swindler known to the police and they insinuate that she can't financially gain from him and therefore needed the money, which is a good motive for the murder.  

Wiesiewicz arrives and asks if his wife was here.  Marek says yes, then Ms. Mantler interjects that his wife came to see him at three o'clock.  However, he was not in his office.  Mrs. Wiesiewicz joins them and her husband asks her whether she was actually at the ministry at three o'clock, which she denies.  She claims to have been looking for her husband, u. a. in the library, but he was actually there, during that time.  
Since the Wiesiewicz's contradict each other this much, Marek and Wirz question the two in more detail.  Wiesiewicz was with Radler the hour before his death.  Radler poured both of them a cognac, but Wiesiewicz didn't drink it.  Ms. Mantler brought in the glasses and the cognac bottle.  The examination showed that there was no poison in the bottle.  Radler must have been given the poison in the glass.  Wiesiewicz denies having poisoned Radler.  Before Radler drank his cognac, the two of them went to see section chief Ehmann.  Both glasses initially remained full.  One of the glasses spilled on the desk and Radler wiped it off with a handkerchief.  Wiesiewicz admits he accidentally spilled his glass after section chief Ehmann's return.  Radler then drank his cognac on his own because he got a taste for the cognac from section chief Ehmann.  Then, Wiesiewicz had to watch how section counselor Radler died in agony.  The glass that he knocked over was his own and Radler drank his cognac.  Wirz asks Wiesiewicz how long he'll stay as a ministerial advisor.  Wiesiewicz says he is ambitious.  

Marek asks Mrs. Wiesiewicz again, about the poison she bought for the garden.  The housekeeper showed the police the glass, but it was empty.  Mrs. Wiesiewicz has no explanation.  Wirz confronts Wiesiewicz about the fact that he put poison in his own glass and then knocked Radler's glass over so that he could drink his cognac.  Marek presents the poison that has disappeared from the Wiesiewicz house.  It' lacks just 'the amount needed to kill Radler.  Mrs. Wiesiewicz admits that this is her poison.  She starts crying because she can't help her husband.  Mr. Wiesiewicz then confesses to both murders.  The motive was ambition and he said that his wife always thought he was a weakling.  Mr. Wiesiewicz is' taken away.

The next morning Marek and his team get a call.  Mr. Wiesiewicz hanged himself in custody.  Marek goes to Mrs. Wiesiewicz to bring her the news of his death.  Marek confronts her with the fact that he thinks she is the perpetrator, her husband confessed to the deeds only out of love for her, when he realized that she was the perpetrator.  Marek explains that in his eyes she' had to have been the 'murderer because she knew that if he made a false confession he would kill himself.