Jensen's a former police detective, let go from the department for reasons that aren't immediately clear. His former coworker and friend Aldis got him a job with a security company, scanning camera footage. One camera is outside HQ of a mob boss, and Jensen notices a messenger making a regular delivery. He notes the kid takes excellent care of his bike, always locks it securely to a pipe or something permanent before he takes his delivery inside, no matter how long he'll be gone.

And then the kid...just doesn't come for the bike. Jensen scans the footage every day, and the bike's still chained up. He gets worried about the kid, and convinces Aldis to use police sources to find out what he can about the kid, and turns out, he hasn't been seen for a few days. Detective work and intuition tells Jensen the route the goons would have taken to get rid of the kid and he and Aldis go looking. They find the kid--Jared, and he's badly injured. They can't take him to the hospital because mob spies, and nobody knows who Jensen is, so they take him to Jensen's and call in discreet doctors, and Jared's set to recuperate at Jensen's. Getting to know each other is prickly. And Jared eventually finds out what made Jensen so aware that something must have happened to him.

I can't recall the title nor the author, but hopefully this rings a bell for somebody.