Immortalised in Christopher Isherwood's classic novel Mr Norris Changes Trains, Gerald Hamilton was the real-life model for the seedy but beguiling Mr Norris. Isherwood put him on the literary map but he was on other maps already, including those of police forces across Europe, and he was interned in Brixton prison during both world wars as a threat to national security. A Communist agent in the Thirties, Hamilton later drifted to the right and put...