When the outlaw Nathaniel McBain was finally brought to justice, it was by his old boss and friend Sheriff Cassidy Yates. Nathaniel got seven years in jail and when he finally came out he resolved to go straight.
He did just that and with Shackleton Frost he delivered prisoners to his former jail with distinction. Then one day he was given the mission he had dreaded of taking custody of a prisoner from Monotony, Cassidy's town. The prisoner escapes and worse, Shackleton ends up dead. Nathaniel vows revenge, but to succeed in his mission he must team up with Cassidy Yates, a man he had never wanted to meet again.