From Gunpowder. Unlikely Heroes, #2

Their case may be getting cold, but their feelings for each other are just warming up. When Macie Greene gets a job in the office at the police station, she never expects to be put on a case due to her hyper-observant eyes and ears. After all, she's just a receptionist. But when she solves a case no one else can, she soon finds herself with a new job, and a new partner-the gorgeous, but standoffish, Tad Simmons. Tad isn't thrilled to have his solo gig interrupted by the new hire.
He's spent his entire life trying to prove that, despite his partial blindness, he's better than anybody else at this game. Macie's involvement threatens the careful career he's built for himself. Not only that, but with her weird humor and self-effacing genius, she might even threaten the safe spaces he's built around his heart. However, when they both agree that a murder-suicide isn't what it seems, they're stuck working together.
Trying to find enough proof of a murder-murder before the flicker of feelings between them gets too hot, or the case goes completely cold. And all they've got for witnesses are a few nasty relatives, some boring phone messages, and a missing dog...