Trotsky's son Leon Sedov lived in Paris, where, in 1936, there was a branch of the IISH on the Rue Michelet. He arranged for the transfer of parts of his father's archive to the Institute. Only four people knew about this precarious transaction. And one of these worked for the Soviet secret police, the GPU. In the night of 6 -7 November 1936, a part of Trotsky's papers was stolen from the Rue Michelet. The directors of the IISH tried to play down the news by saying that they contained printed matter of no importance. This was partly untrue. To enhance security, later acquisitions of collections related to Trotsky were given the code name of ABEL. This went well with KAIN, the name Trotsky used for Stalin.