In Paris, a woman is making enquiries : why did leftist Alfred Katz simply disappear in 1938 ? In that year, Alfred, is politically active in a Parisian Trotskyite cell. Hitler's Non-Aggression Pact with the Soviet Union has heightened the tension between local supporters of Trosky and Stalin. Alfred attends a wild party being held by surrealists. There he meets Mila, a glamourous and uninhibited prostitute from the brothel called the "Sphinx". Alfred soon meets Mila's other lover too, Félix... An American comrade and her Belgian companion arrive to establish a direct link between the cell and Trotsky in Mexico. As prominent Trotskyites begin to die or disappear, Alfred and Mila marry. Has an agent of Stalin's secret police infiltrated the group ?