When a neurosurgeon is assassinated just before performing surgery, Five-0 uncovers the shocking truth behind the disappearance of four reform school boys 40 years ago. Also, McGarrett's Mercury Marquis is stolen by an unlikely culprit.

While Five-0 hunts for a notorious criminal who has never been seen, Kono must fight for her life when she discovers the villain's identity. Also, Kono confesses to Adam that she's conflicted about their future together because of his ties to his formerly corrupt family business.