Paul Cain was the nom de plume of Iowan George Carol Sims. He was the author of seventeen crime fiction short stories collected in the magazine  Black Mask and one novel, Fast One. Also wrote screenplays as Peter Ruric, including The Black Cat for Karloff & Lugosi. 

"Swanstrom was sitting at the desk with his back to the door. Another man, a spare, thin-haired consumptive-looking man, was sitting on a chair on the platform, one of the .30-30s across his knees. He looked at Kells and he looked at the big blue revolver in Kells' hand and he put the .30-30 down on the platform."

- Paul Cain