Voight finds himself up against a younger, more violent version of himself, after retired Commander Perry asks him to help extract his cop nephew from a unit of corrupt narcotics officers. Lindsay is sent on an undercover sting.
Danny begins an extra job working as a bodyguard which turns into a case while Frank feels the pressure to promote Gormley and Jamie reflects on staying with Eddie.
McGarrett and the Five-0 are captured while tracking a dangerous nemesis to the island of Lanai; Grover takes his son to Chicago, where he testifies against a dirty cop.
The team links a bizarre crime scene at Arlington National Cemetery to a string of attacks on homeless veterans.