The Zossen train explosion occurred in June 1929 when a Soviet train returning to Russia from Berlin was ambushed by the Black Reichswehr, Berlin Mafia, and Berlin Police in Brandenburg, as the result of several conspiracies unraveling concurrently. The Soviets intended to return the train to their territory to cover up their involvement in a failed coup attempt in Germany, the German nationalists sought to recover the phosgene gas and gold stashed on the train to plan another coup, the Berlin Mafia sought to steal Countess Svetlana Sorokina's gold, and the Berlin Police sought to prevent a coup and deal a major blow to the Black Reichswehr. Ultimately, the Mafia massacred the nationalists, the mobsters fled after many of them died from a leak of the phosgene gas, and the policeman Gereon Rath killed his corrupt colleague Bruno Wolter as he attempted to escape. The Soviet ambassador Denis Trokhin and his Cheka henchmen later recovered the train, only to be disappointed when they found that the gold was fake.
Background[]
By 1929, Weimar era Germany was in a state of political chaos. The democratic government of Germany faced the dual threats of revolutionary communism on the far-left and reactionary nationalism on the far-right, while, within the left-wing, Trotskyists, Stalinists, Leninists, and anarchists each violently disputed the course of the revolution started in 1917. At the same time, organized crime became immensely powerful in Berlin, engaging in the blackmail and extortion of public officials such as Lord Mayor of Cologne Konrad Adenauer, and having great influence within the Berlin Police.
Among the most potent threats to Weimar democracy during the 1920s was the Black Reichswehr, a nationalist shadow army led by Major-General Wilhelm Seegers. Seegers, while a staunch monarchist and anti-communist, was willing to work with the Soviet Union to achieve his goal of overthrowing the liberal democratic regime in Berlin and restoring Kaiser Wilhelm II of Germany to the throne, with General Erich Ludendorff as Chancellor. Starting in 1925, Black Reichswehr agent Major Anton von Beck made dozens of visits to the Russian SFSR, where the Soviets allowed the Black Reichswehr to establish the Lipetsk fighter-pilot school near Moscow in exchange for the Germans training the Soviets in building aircraft engines. The Germans began to assemble a modern air force in contravention of the Treaty of Versailles, while the Nyssen AG company, led by Annemarie Nyssen and her son Alfred, secretly imported weapons (from small arms to tanks and heavy guns) from Russia by train. Seegers signed off on these trains as they crossed the German border, ensuring that his Black Reichswehr could stockpile weapons near the Nyssen estate and prepare for a counter-revolution.
The Trotskyists adding the golden carriage to the train
By April 1929, Seegers' plan for a monarchist coup - codenamed Operation Prangertag - was on the verge of execution. Nyssen arranged for a Soviet train to smuggle thirteen wagons of phosgene gas (Green Cross) across the German border, with the gas disguised as pesticides. At the same time, however, the infighting between Trotskyists and Stalinists within the world communist movement led to the leader of the Trotskyist Red Fortress organization, Alexei Kardakov, collaborating with the countess Svetlana Sorokina, a Cheka double agent posing as a Trotskyist, to smuggle her hoard of gold to Leon Trotsky in Istanbul by way of Germany. Red Fortress members Boris Volkov and Ivan Tyumenev ambushed the Soviet train near Novorzhev on 29 April 1929, killing two of the crewmembers and disguising themselves in their uniforms. They saw to it that the Sorokin family's carriage, containing great quantities of (unbeknownst to everyone, false) gold bars, was latched onto the train, and they resumed their voyage.
When the train reached the German border on 30 April, Major-General Seegers and Major Beck, unaware that the train had been ambushed, signed off on its entry into Germany, believing that their arms shipment was arriving according to plan. The train arrived at the Anhalter train depot in Berlin on the morning of 1 May. Meanwhile, on hearing of the train reaching the border, Kardakov brought Sorokina to the Red Fortress hideout in a basement print shop at Koepenick in Berlin, where the Trotskyists celebrated their plan nearly coming to fruition. Sorokina proceeded to inform the Soviet ambassador Denis Trokhin of the location of the Red Fortress hideout, and Trokhin sent his Cheka agents Grigori Selensky and Mikhail Fallin to wipe out the 15 Trotskyists at their print room. Kardakov survived the massacre by hiding in a latrine, and he later survived Sorokina's attempt to shoot him dead after he came to her for vengeance. Sorokina had the carriage of the train rerouted to Paris rather than Istanbul, causing Volkov to accuse her of betrayal and run off with the train's travel documents, preventing it from moving on to Paris. He was later captured by the Cheka and tortured to death, and the Berlin Police's discovery of his body at the Spree river's Landwehrkanal led to policeman Gereon Rath and police typist Charlotte Ritter opening an investigation.
Meanwhile, Kardakov attempted to have his vengeance against Sorokina by approaching Berlin Mafia boss Edgar Kasabian and telling him about the gold bars in Carriage 3221. Kasabian sent henchmen to open the carriage, only to find that the number had been mislabelled; when they broke into the carriage, it exploded, as it contained phosgene gas rather than gold. The explosion attracted police attention, and Rath and Ritter drew a connection between Kardakov, the train, and the murder of Volkov.
At the same time, the discovery that the train contained phosgene gas illegally imported from the USSR by Alfred Nyssen himself led to political police chief August Benda having Nyssen arrested. This created a scandal within the business community, and Nyssen was removed from his company's board on his release from jail. At the same time, the Berlin Police discovered the mass grave of the massacred Trotskyists and arrested the two Chekists responsible. Benda and Rath blackmailed Trokhin into giving up the names of the Black Reichswehr leaders to whom he had smuggled weapons in exchange for releasing the Chekists and covering up the massacre, as the publicization of the massacre would likely lead to Joseph Stalin having Trokhin executed. Trokhin gave up the names of the top fifteen leaders of the Black Reichswehr, who were promptly arrested. However, the far-right's influence in the government and police led to the Black Reichswehr leaders being released just days after being arrested and interrogated.
The Black Reichswehr decided to go along with their plan to overthrow the Weimar regime with Operation Prangertag, during which they would assassinate the German and French foreign ministers during a 30 May 1929 opera performance, lower the Weimar flag over the opera house, have General Kurt von Schleicher activate the 1st and 2nd Military Districts and seize the Reichstag and police headquarters, arrest democratic military and political leaders, name Ludendorff as chancellor, and return Kaiser Wilhelm II from exile. The plot involved policemen Bruno Wolter and Florian Scheer infiltrating the opera house and using illegal sniper rifles to assassinate the two ministers as a gunfight scene from The Threepenny Opera occurred on the opera stage. Rath caught wind of the coup plot and incapacitated Scheer, while Wolter's plot to kill Aristide Briand failed when Briand, bored with the opera, got up to leave during the performance.
The coup's silent failure did not perturb the Black Reichswehr leadership, who continued to plan their uprising. Benda resorted to having Seegers presented before a press conference where the train's entry document with Seegers' signature would be presented to the public as proof of the general's guilt, but President Paul von Hindenburg returned from a trip and arrived at the police headquarters just before the conference could begin. Hindenburg forced Benda to postpone the press conference as he took Seegers with him, effectively rendering the public ignorant that a coup attempt nearly happened, and preventing the Black Reichswehr or any of its leaders from being incriminated.
Hindenburg also ordered that the Soviet train be immediately released, thus removing any physical evidence of the Black Reichswehr's plot to import Soviet weaponry for a coup and helping his nationalist friends. Sorokina persuaded Alfred Nyssen that the Black Reichswehr could ambush the train on its way back to Russia and recover its phosgene gas and gold, while Kasabian had his men kidnap Ritter, who revealed that the gold was in another mislabelled carriage, thus motivating them to go after the train as well. Finally, Rath and his friends in the police decided to go against official orders to leave the train alone and intercept it, hoping to prevent the corrupt Wolter and his friends from getting their hands on the phosgene gas and gold.
History[]
The Black Reichswehr and Mafia separately planned to ambush the train at Milestone 127, in the direction of Wunsdorf. Ritter, released by Kasabian, told Rath and his colleagues of these plans, and they drove in separate cars to ambush the train. While Wolter rammed Rath and Ritter's car off the road and into a lake before fleeing, Rath and Ritter escaped and traveled with Thorsten Henning and Rudiger Czerwinski in their car. Rath left Ritter to recover as he, Henning, and Czerwinski continued on to Milestone 120, where they activated a "stop" sign. While the train was stopped, they snuck aboard, riding with it to Milestone 127.

The Black Reichswehr holding up the train
There, the train was halted by around a dozen Black Reichswehr soldiers, who parked vehicles on and adjacent to the tracks. Wolter went into the gold carriage to examine the gold as Major Von Beck and his men stood guard outside. The Berlin Mafia, hiding in the grass, used silenced guns to massacre Von Beck and his men, and they forced Wolter to leave the train before shooting him and wounding him. Rath, who was confronting Wolter in the gold carriage, was also forced to leave the train by the mobsters, but Kasabian had his men spare Rath. At the same time, bullet holes in the phosgene containers began to leak gas and kill several mobsters, forcing Kasabian and the surviving mobsters to flee. Rath and his colleagues donned gas masks, and, when the train driver activated the train and attempted to flee, Rath stayed on the train to confront a missing Wolter as he had Henning and Czerwinski disarm the dead mobsters.
The train continued down the tracks towards Zossen, where Rath and Wolter - having taken a pistol from a dead paramilitary - engaged in a gunfight. Wolter unlatched the first two cars from the rest of the train, hoping to escape to Russia, but Rath shot a bullet next to Wolter as he smoked a celebratory cigarette. The cigarette fumes ignited the phosgene in the second car, causing a massive explosion that killed Wolter and attracted national attention to the train's existence.
Aftermath[]

The investigation of the train explosion
As the existence of Operation Prangertag, the Black Reichswehr plot to smuggle chemicals from the USSR into Germany, and the Red Fortress plot to fund Trotsky's revolution were all kept under wraps by the police, the explosion of the train near Zossen appeared to be an unremarkable accident involving an ordinary train. Trokhin and his Chekists found the separated cars of the train and were infuriated to find that the gold bars were all gilded coal; in fact, the carriage itself was made of the Sorokin family's gold, and Sorokina - herself an impostor - was unaware of this. The Soviets took the remains of their train back to Russia, while the Black Reichswehr were forced to bide their time and await another opportunity to overthrow German democracy. At the same time as the train explosion, Benda was assassinated in a Nazi bombing attack blamed on the KPD, who claimed that the attack was revenge for the Blutmai massacre of 1 May 1929. The new political police chief, Gottfried Wendt, created a new police department focused on maintaining the political neutrality and incorruptability of the police and appointed Rath to informally head it, as Wolter's involvement in the Black Reichswehr plot indicated that many policemen let their politics influence their actions. Sorokina traveled to Paris to continue her musical career - and perhaps her Cheka agency - there, as her purpose in Berlin was at an end due to the destruction of the Red Fortress and the loss of what she believed was the Sorokin family's gold hoard.