Dr. Emily Hartford is back in Chicago, ready to move forward and leave the past behind, until an unexpected request for help sends her deep into an investigation—and into the path of a killer.

Seventeen months after the Parkman case, Dr. Hartford has returned to Chicago to finish her surgical residency. But when she is contacted out of the blue by Solange McClelland, the only survivor of a decade-old triple homicide, Emily is compelled to dig deeper. She doesn't know the details of the event but remembers it as one of the few cases her deceased father never solved.

On her thirtieth birthday, Solange opens a long-forgotten safe-deposit box and is entirely baffled by what she finds. Inside are not only painful reminders of a once-happy youth but almost four million dollars—enough to pursue and finally solve the mystery of who brutally murdered her family. It's been over ten years, and Solange has built a new life in Detroit with her husband, Joseph. But there are certain disturbing questions about her past that she is determined to answer. So she reaches out to the only one who might know something about her family's deaths and their possibly erroneous death certificates—Dr. Hartford, the daughter of Freeport's former medical examiner.

Finding it impossible to believe that her scrupulous father made a mistake, Emily joins Solange's pursuit of the truth, and as subzero temperatures blanket snow-covered Michigan, the two women pursue justice in two very different ways. But lurking nearby in the frigid cold is a crafty, unrepentant killer, determined to finish what he started long ago.