Sharon McCone spent most of her last appearance, Locked In, unable to move or speak after being shot in an apparent robbery. Coming Back picks up six months later. Sharon is weak and easily tired, but back to work and chafing against the coddling she's getting from her employees and her husband. Left with few responsibilities in the office, it's natural that she would take on the odd disappearance of one of her friends from rehab.
When Piper Quinn missed nearly a week of PT, Sharon decided to check up on her. She saw Piper, apparently drugged and in the care of someone claiming to be Piper's aunt. But the aunt didn't exist, and when Sharon returned to the apartment, it had been emptied, cleaned and repainted She called her main operative, Adah Joslin, to follow up, and leaves to follow another lead. Several hours later, when Adah's partner Craig (also a McCone investigator) realizes that Adah is missing and probably kidnapped, he calls an emergency meeting and the team set out to find Adah - and Piper. But who would want to kidnap a web designer disabled by a hit-and-run driver? The solution involves a little too much conspiracy for my taste, but it was well constructed and supported, and I figured it out as it was revealed.
Muller used a multi-narrator technique with Locked In and uses it again here. The shifting narrators (Sharon, Adah, Craig, Sharon's husband Hy Ripinsky, her nephew/employee Mick Savage, and her friend and office manager Ted Smalley) keep the pace quick by minimizing the exposition. They also allow us to know these characters more fully than if we'd only seen them through Sharon's eyes. There's a lot of introspection between, even during, the action scenes and it makes for an interesting novel as well as the literary equivalent of an action movie. I read Coming Back in a single day, and would have read it in a single sitting if I didn't have to go to work.