Last to Die by Tess Gerritsen

In Boston, a teenage boy named Teddy Clock is the only survivor when his foster family is murdered in their home. Detective Jane Rizzoli is called to the site. As she delves into Teddy's background, she discovers that he was also the only one left alive two years ago when his family's yacht blew up in St. Thomas. Teddy is not suspected in the crimes, but it gets Jane wondering about Teddy's past. With medical examiner Maura Isles' help, Jane discovers two other kids, Claire Ward and Will Yablonski who have backgrounds similar to Teddy's. Claire and Will live at a school called Evensong, secure and isolated, in Maine. Interspersed throughout the book are scenes set in Italy about a character named Icarus, who an anonymous narrator is trying to capture. What is the connection between Icarus and the teens and how will Jane and Maura keep the kids safe since it seems someone might be after them?