The Puzzling Case: The Printed Playing Card

"Captain, we can't find Old Du's sniper rifle. The killer must have taken it with him, but we found this beside his body."

Xie Yunhai pulled a printed playing card from his pocket and handed it to Chen Jun.

The back of the card bore a purple-and-gold rose pattern, while its face showed a grinning gray clown. Blood from Du Weifeng had stained the card, making the clown's smile look especially twisted and sinister.

Chen Jun stared at the bloodstained joker, an invisible murderous aura flashing in his eyes.

Although Chen Jun and the others often gathered at home to play cards, all the brothers knew that Old Du never played. In other words:

The killer had deliberately left this printed card behind!

A provocation!

This was a blatant provocation by the killer!

Who was this killer?

This novel and its characters are entirely fictional. Any resemblance to actual people or events is purely coincidental. Do not imitate.