Marker — Robin Cook

As her relationship with Dr. Jack Stapleton begins to unravel, Dr. Laurie Montgomery starts investigating the inexplicable deaths of young, healthy people after successful routine surgery. She discovers that the deaths might be intentional--the work of a remarkably clever serial killer with a shocking motive. And then Laurie is hit with more devastating news: She might be carrying the genetic marker for breast cancer. As the need for answers becomes more urgent, Laurie is pulled into the nightmare as a potential victim herself. With time winding down, she and Jack must put aside the tensions between them in a race to connect the dots--and save Laurie's life...