Riding peacefully along a western trail, Lucky Luke is suddenly ambushed by an unknown assailant. After a quick gunfight, the cowboy loses his mysterious attacker, but happens upon a lone wagon beset by Apache raiders. Another quick fight later, Luke is surprised to find that the occupants of the wagon are three lovely young women! Three sisters on their way to start a new life, and who all find the lonesome cowboy … quite interesting.

The Lonesome Cowboy is not having a good day. Out of tobacco, arriving at night and under pouring rain in the small mining settlement of Froggy Town, he soon finds himself in conflict with two of the Bone brothers, somewhat infamous local figures. Unfortunately, Luke’s reputation precedes him, and when the townspeople ask him to investigate a hold-up in place of the sheriff – none other than James Bone – the tension ratchets up another notch …