Although the MASK traffic ended, as far as GC&CS was concerned, in January 1937, further Comintern messages were intercepted during the Second World War and were designated ISCOT. Naturally, as Stalin by then had joined the Allies, the cryptographic work undertaken on the top floors of Aldford House, overlooking Park Lane, was considered highly secret, and the small team of codebreakers, led by the Cambridge mathematician Dr Bernard Scott (later Professor of Mathematics at Sussex University), were isolated even from GCHQ's Diplomatic Section, which was also located in Mayfair, above Madame Eleda's couturier in Berkeley Street. Actually, ‘Madame Eleda’ was Adèle Croft, the mistress of a member of the Baring banking family, himself working as an intelligence offcer.