As a reader take these suggestions.

[in nor particular order]

'Red Harvest' by Dashiell Hammett. A tough detective arrives in a lawless town and proceeds to clean it up by tricking half the town into killing the rest. If the plot sounds familiar it's because people stole it from this book, the original.

'Night's Master' by Tanith Lee. A demon prince spends his night's seducing and tormenting humans. Like Neil Gaiman? He stole a tone of stuff from her.

'Dark Star' by Alan Furst. On the brink of WW2 a Soviet reporter is drafted into the KGB. He's lead to a mysterious suitcase and soon finds himself hunted across Europe.

Enjoy.