The secret town of Rockton has seen some rocky times lately; understandable considering its mix of criminals and victims fleeing society for refuge within its Yukon borders. Casey Duncan, the town's only detective on a police force of three, has already faced murder, arson and falling in love in less than the year that she's lived there. Yet even she didn't think it would be possible for an outsider to find and cause trouble in the town she's come to call home.

When a US Marshal shows up in town demanding the release of one of the residents, Casey and her boyfriend, Sheriff Dalton, are skeptical. And yet only hours later, the marshal is shot dead and the only visible suspects are the townspeople and her estranged sister, in town for just the weekend. It's up to Casey to figure out who murdered the marshal, and why they would kill to keep him quiet.