His ‘jaw was long and bony, his chin a jutting v under the more flexible v of his mouth. His nostrils curved back to make another, smaller, v. His yellow-grey eyes were horizontal. The v motif was picked up again by thickish brows rising outward from twin creases above a hooked nose, and his pale brown hair grew down – from high flat temples – in a point on his forehead. He looked rather pleasantly like a blond satan.’ Sound familiar? Sam Spade? Samuel D Hammett.

It’s always an error, of course, to associate authors too closely with their characters, but some authors come much closer than others and positively dare us to make the association: everywhere you look in literature, it seems, there are writers challenging us to interrogate their alter egos, doppelgängers, self-portraits and sock puppets. Zuckerman, are you really Philip Roth? Birkin, are you Lawrence? Maggie Tulliver – is that you, George?

Samuel D – Dashiell – Hammett provides readers with at least two possible self-portraits, Sam Spade and the Continental Op, the hard-boiled heroes of his most famous novels and short stories, Red Harvest (1929), The Dain Curse (1929), The Maltese Falcon (1930) and The Glass Key (1931). There’s also his