Operation Spark (sometimes translated as "Operation Flash") was the code name for the planned assassination of Nazi dictator Adolf Hitler by the anti-Nazi conspiracy of German Army officers and political conservatives, known as the Schwarze Kapelle ("black orchestra") during World War II.
Hitler's death, however, would be a "spark"—a signal that it was time to launch an internal coup d'état to overthrow the Nazi regime and end the war.
Tresckow was now serving as Chief Operations Officer of Army Group Centre (AGC) on the Eastern Front.
AGC commander Günther von Kluge knew of Tresckow's activities, but did not denounce him to the Gestapo, nor participate himself.
For such an occasion, Tresckow had prepared three options: The bomb was adapted from a British plastic explosive, which had been seized by the Abwehr from captured SOE agents.
When the crash and Hitler's death were reported, General Olbricht would use the Replacement Army to seize control in Berlin, Vienna, and Munich, and in the centres of the Wehrkreis (the German military supply system).
The model was to be Axel von dem Bussche, who volunteered to carry a landmine in the knapsack of the uniform, and detonate it when the three Nazi leaders were gathered around him.
Nonetheless, the freight car containing the new uniforms was destroyed in an Allied air raid the night before the scheduled demonstration.
Meanwhile, von dem Bussche had to return to front-line duty, and was badly wounded, losing part of one leg, so he could no longer serve as model.
Captain Eberhard von Breitenbuch was on the staff of Field Marshal Ernst Busch, now commanding Army Group Centre.
Breitenbuch volunteered to carry a 7.65mm Browning pistol concealed in his trouser pocket into the briefing (which took place on 11 March), and shoot Hitler.
SS Chief Himmler immediately launched an inquiry into the incident which was deliberately blocked by Lieutenant Colonel Werner Schrader–the investigative officer in charge and, as it turned out, a fellow conspirator.