Death Watch by Mike Ryan

A security guard at Mia's hospital has gone missing. She brings in Recker and the team to help investigate what happened, and they quickly realize there is a lot more to this case. They soon learn the guard is just one of many who have gone missing, all being found under the same conditions. And their findings will take them straight into the arms of a serial killer, who's got a long list of targets. How many will lose their lives before the Silencer team can find their suspect?