A desperate entity trapped on the other side of an active hellmouth pleads for cougar shifter Belle Foye's help, and she can't stop herself from running toward it, even though it means putting her own life in danger. As if that weren't inconvenient enough, Belle's inner cat's biological clock is loudly ticking, which means her body is acting in all sorts of ways she wishes it wouldn't—particularly when it comes to her new babysitter.

Former soldier Steven Welch has been tasked with keeping Belle away from the hellmouth at all costs. It's just his luck that the cat has taken a shine to his human self. Unfortunately, sticking close to her means he has no choice but to confront a fear of the supernatural he'd hoped he left in the Afghan desert.

When the pair learns Steven's own secret paranormal gift could help solve Belle's problem, their differences collide. Steven insists he's no hero, but Belle wants to enter the hellmouth and end the trouble it's brought on her family once and for all.

If Belle can't convince him that she has his back as well as he has hers, she'll lose her fated mate and the only man she's ever trusted enough to call "partner."