In a plane to Moscow, Boris, the Russian agent of the FSB that XIII knew in his youth during his infiltration into Cuba, reminds our hero of an old mission that his memory had erased. By stimulating the lost memory of Jason Mac Lane, the Russian hopes to discover the hiding of an old proof of conspiracy that could be useful to revive his career. In 1984, in the time of the cold war, XIII had been sent to kill a candidate for the Russian presidency judged a little too conservative by the American government in the framework of the plan of warming of East-West relations. But the planned attack at a reception at Spaso House, the Moscow residence of the American ambassador, had failed by the fault of a sub-agent of the KGB, Nina Orekhova, alias "Babotchka" (a butterfly). This last, seeing in the word Mac Lane a young idealist, glides into his hands a microcasssette containing evidence of complicity of Russian and American billionaires in a trade of weapons and military technologies infiltrated between the Soviets and the Americans party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of the party of party of party of party of party of party of party of party of party of party of party of party of party of party of party of party of party of party of party of party of party