Criss Cross - James Patterson

nWhen a mysterious serial killer known as M launches a deranged investigation, Alex Cross and his partner must unearth long-forgotten secrets to survive -- or risk getting buried themselves. nIn a Virginia penitentiary, Alex Cross and his partner, John Sampson, witness the execution of a killer they helped convict. Hours later, they are called to the scene of a copycat crime.

A note signed M rests on the corpse. You messed up big time, Dr. Cross.

nWas an innocent man just put to death? Alex soon realizes he may have much to answer for, as M lures the detective out of the capital to the sites of multiple homicides, all marked with distressingly familiar details -- details that conjure up decades-old cases. Details that conjure up Cross family secrets.

Details that make clear that M is after a prize so dear that -- were the killer to attain it -- Alex's heart would no longer have reason to beat.