The Gutter And the Grave by Ed McBain
Apparently McBain used to write pulp fiction. One of his earliest novels and certainly not his best, The Gutter And the Grave reads like a Mickey Spillane story in places, though you can see glimmers of his future talent. Lots of plot twists but of course you know the girl dunnit in the end and the detective/bum goes back to his drinking. Predictable and formulaic but written with McBain’s usual smooth flow.