Der Untergang

The film begins with an excerpt from the documentary Blind Spot: Hitler's Secretary (2002), featuring the real Traudl Junge expressing her guilt and shame for admiring Hitler in her youth. The film continues showing Hitler (Bruno Ganz) hiring Junge (Alexandra Maria Lara) as his secretary at the Wolf's Lair in East Prussia in November 1942.
The story resumes on 20 April 1945, the FÃ¼hrer's birthday, during the Battle of Berlin. A loud artillery blast wakes up Traudl, Gerda Christian and Constanze Manziarly in the room they share. Down in the FÃ¼hrerbunker, Hitler is informed by Wilhelm Burgdorf that Berlin is under attack and then by Karl Koller that the Red Army has advanced to within 12 kilometres (7.5Â mi) of central Berlin.
At Hitler's birthday reception, ReichsfÃ¼hrer-SS Heinrich Himmler and his SS adjutant Hermann Fegelein plead with Hitler to leave the city. Instead, Hitler declares, "I will defeat them in Berlin, or face my downfall." Himmler leaves to negotiate surrender terms with the Western Allies, behind Hitler's back. In another part of the city, a group of Hitler Youth members are bolstering defenses. Peter, one of the members, is urged by his father to desert but refuses.
In yet another part of the city, SS physician Ernst-GÃ¼nther Schenck convinces a general to allow him to ignore an evacuation order and is then requested by BrigadefÃ¼hrer Wilhelm Mohnke to bring any available medical supplies to the Reich Chancellery. Meanwhile, Hitler discusses his new scorched earth policy with his Minister of Armaments, Albert Speer, while Eva Braun holds a party for the bunker inhabitants that is broken up by artillery shells.
The next day, while his unit is fighting off the Red Army, General Helmuth Weidling is summoned to the bunker to await execution for ordering a retreat to the west. After explaining to Hans Krebs and Burgdorf that it was a misunderstanding, Weidling is promoted by Field Marshal Wilhelm Keitel to oversee Berlin's crumbling defences. Hitler orders an attack from Felix Steiner's unit to stem the Soviet advance â army groups which at this point only exist on paper. Later, Hitler is informed by Krebs and Alfred Jodl that Steiner physically could not mount the attack. Dismissing everyone from the room except for Keitel, Jodl, Krebs, and Burgdorf, Hitler flies into a furious rage against what he perceives are traitorous actions against him and finally acknowledges that the war is lost. However, he is determined to stay in Berlin to the bitter end, even if it means killing himself, saying "But, gentlemen, if you believe I'm going to leave Berlin, you are seriously mistaken. I'd rather blow my brains out."
After seeing conscripted civilians of the Volkssturm needlessly gunned down in battle, General Mohnke confronts Joseph Goebbels, their commander, about the slaughter. Goebbels tells Mohnke that he has no pity for the civilians, as they chose their fate. Hitler loses his sense of reality and orders Field Marshal Keitel to find Admiral Karl DÃ¶nitz, who Hitler believes is gathering troops in the north, and help him plan an offensive to recover the Romanian oil fields.
Later on, Martin Bormann interrupts a meeting between Hitler, Goebbels, and Walther Hewel to read a message from Luftwaffe chief Hermann GÃ¶ring requesting permission to assume command and become head-of-state. Hitler responds by stripping GÃ¶ring of his rank, ordering his arrest, and naming Robert Ritter von Greim as his replacement. Hitler then receives further upsetting news when Speer informs him that he has defied Hitler's scorched earth policy orders. Hitler does not punish Speer, but he does not shake his hand as Speer leaves.
At dinner, Hitler receives a report that Himmler has contacted Folke Bernadotte in an attempt to negotiate surrender. Hitler orders von Greim and his mistress, test pilot Hanna Reitsch to find Himmler and that his adjutant Fegelein to be brought to him. After being informed by Otto GÃ¼nsche that Fegelein has deserted, Hitler orders Fegelein executed for treason.
Reichsphysician SS Ernst-Robert Grawitz, the head of the German Red Cross also responsible for Nazi human medical experiments, asks Hitler for permission to evacuate Berlin for fear of reprisal from the Soviets for his actions. When he does not get it, Grawitz goes home and kills himself and his family with grenades. That night, Fegelein is arrested and executed by an RSD squad.
News grows even grimmer as Weidling reports to Hitler there are no reserves left, and Mohnke reports that the Red Army is only 300 to 400 metres from the Reich Chancellery. Hitler reassures the officers that General Walther Wenck's 12th Army will save them. After Hitler leaves the conference room, the generals all agree that is impossible. After midnight, Hitler dictates his last will and testament to Traudl, before marrying Eva Braun. Hitler orders Goebbels to leave Berlin, but Goebbels refuses.
Hitler summons Dr. Schenck, Dr. Werner Haase, and nurse Erna Flegel to the bunker to thank them for their medical services for the wounded. Dr. Haase explains to Hitler the best method for suicide as well as for administering poison to Hitler's dog, Blondi. Hitler eats his final meal and then bids farewell to the bunker staff. He then gives Magda Goebbels his own Golden Party Badge Number 1. Emotionally overcome by the gesture, Magda tries to convince Hitler to reconsider suicide, but Hitler does not. Hitler and Eva then kill themselves and, as per his orders, are cremated in the Chancellery garden.
Meanwhile, Krebs meets with Marshal Vasily Chuikov of the Red Army to negotiate peace terms but returns unsuccessful. Goebbels berates his generals, reminding them Hitler forbade them to surrender. Hans Fritsche leaves the room to try and take matters into his own hands, only to nearly be shot by an angry Burgdorf.
After this, with the help of SS Dr. Ludwig Stumpfegger, Magda kills her six young children with cyanide. She and her husband then walk up to the Chancellery garden, where Goebbels shoots his wife and then turns the gun on himself. The remaining staff in the bunker begin to evacuate, while Krebs and Burgdorf commit suicide. Weidling broadcasts to the city that Hitler is dead and that he will be seeking an immediate ceasefire.
Traudl, Gerda, and the remaining SS troops that managed to leave the bunker are sticking with Schenck, Mohnke, and GÃ¼nsche as they try to flee the city. Hewel manages to join them, but after word reaches them of the surrender he and several others shoot themselves. The same thing happens to many others the group comes across. Meanwhile, the child soldiers have all fallen victim to the Soviet charge except for Peter, who also discovers that a Greifkommando or Feldgendarmerie squad has executed his parents.
While the Red Army ranks are only streets away, Traudl decides to leave. Peter pulls her through the masses, but she blunders into a celebrating drunken Red Army soldier. Peter tugs her arm, and she hastens away. At a ruined bridge, Peter finds a bicycle and they pedal away from Berlin. The epilogue then tells the fates of the other characters and one final excerpt from the 2002 documentary, where the real life Traudl appears before the credits.

Question: Who explains the method of suicide to Hitler?
Answer: Dr Werner Hasse