Beware the Thirteenth Stroke

A dead man found with all his blood drained from him. A strange clock terrified Sam Wilkes, a large detective who had seen his share of combat as well as street action. Blake Conner was an author Sam called in to see if he could provide any insight. He was a clock collector. 

Sam handed him a note. Scribbled on it were the words “beware the clock . . . the thirteenth stroke.”

What did it mean?

 How could a clock frighten a man like Sam? 

Was there any meaning to the fact a skeleton on the clock was carved from human bones?

Blake would regret purchasing the clock from the dead man's heirs. The end will startle you.

This is a short scary story you should read late at night sitting alone in a dark room.