The case against Lenin was always thin. Pereverzev’s evidence, which involved a contract Lenin was alleged to have signed in Berlin at some time in the previous year, turned out to be the raving of a fugitive prisoner of war. The press proffered more fairy tales — Lenin’s sister was a spy based in Salonica, Lenin had been murdered, Lenin’s real name was Mytenbladm or Zederbluhm. Years later, Trotsky remembered July 1917 as “the month of the most gigantic slander in world history.”

In fact, Lenin was far from dead. He used the months in Finland to lay new, ambitious plans. By mid-September, he felt bold enough to slip back into Russia and take up the fight again, this time preparing his lieutenants for a Bolshevik seizure of power. The operation took place on Nov. 7, and that same day the streets of Petrograd were littered with leaflets announcing the triumph of Lenin’s new Soviet regime.

But questions about finance have a way of haunting history’s great men. Lenin relied on secrecy; the Germans let him down. At the end of 1917, Germany’s foreign minister, Richard von Kühlmann, gloated about his country’s role in November’s Bolshevik coup. Berlin, he said, had long schemed to subvert Russia. The challenge had been to find a person who could do the job. The Germans had backed a range of hopefuls, from Finnish nationalists to Central Asian jihadists. “It was not until the Bolsheviks had received from us a steady flow of funds through various channels,” Kuhlmann explained in a frank memorandum, “that they were in a position to build up their main organ, Pravda, to conduct energetic propaganda and to extend the originally narrow basis of their party.”

Lenin’s bank records were scrupulous enough. He protested that he had snubbed every agent the Germans sent him. He insisted (rightly) that his party had triumphed by giving voice and shape to real passions and despairs. Still, cash had been essential. In the summer of 1917, the British estimated that it would cost them 2 million pounds a month to match Lenin’s propaganda effort. The high price had to take account of Bolshevism’s genuine appeal, but even Lenin knew that newspapers and posters did not print and distribute themselves.

That’s where the condoms and lead pencils come in. Lenin could not risk accepting direct bribes, but it was easy for Berlin to supply his agents with commodities and then forget to send the bill. Goods were exported to Denmark (which was legal), the packaging was changed (illegal), and then they were resold to countries where imports from Germany were banned. Part of the profit found its way into the Bolsheviks’ coffers via businesses in Stockholm. A key part here was played by Yakov Fürstenberg, the manager of a Scandinavian-based import-export company whose directors, Alexander Helphand and Georg Sklarz, were known agents of Germany. Though Lenin publicly disdained Helphand, Fürstenberg was one of his closest contacts, his north European fixer.

“Lenin’s entry into Russia successful,” the German spy chief in Stockholm reported to his masters in April 1917. “He is working exactly as we would wish.” But it was Lenin who would win the high-stakes gamble in the end. The kaiser and his ministers were swept away, but Lenin’s empire went from strength to strength. As he had put it years before: “Sometimes a scoundrel is useful to our party precisely because he is a scoundrel.”