Chicago cop Brendan Donovan loves the adrenaline rush of his role on a tactical team. So when he's assigned to an undercover job to ferret out the supplier of a new and deadly sex drug, he's thrilled. His partner is Cilla Marini, a detective he'd met recently during a traffic stop. He's intrigued by Cilla, but his sister told him that Cilla doesn't date cops. Which is exactly what they have to pretend to do. Brendan loves a challenge.

Cilla is shocked to find out that Brendan is her mystery partner. After an incident that forced her to transfer from her district and isolated her from her fellow cops, Cilla knows relationships with cops are off the table. But she's spent far too much time thinking about Brendan since he pulled her over for speeding. Now, not only are they working together, they have to pose as a couple to find the source of the sex drug that's already killed several men.

As the action heats up, Cilla and Brendan don't have to pretend they want each other. But when secrets put them both in danger, will they have each other's back? Or will their quarry divide and conquer them before they can find their way to happily ever after?