The team investigates a shipwreck carrying exotic animals that now threaten the native wildlife on Oahu; Alex sustains a career-ending injury; Kai asks a fish and wildlife agent out on a date.
McGarrett and the team work with an injured police dog that is the only witness to an ambushed drug bust; a former SEAL looks to join the task force.
Danny offers to let Mindy buy the other condo he owns in his building, but becomes jealous when she starts dating Charlie (Tim Daly); Peter thinks the brain surgeon (Tracey Wigfield) he is dating may be too mature for him.
The cyber team investigates when a hacker uses a power outage in Detroit to mask a jewelry store robbery-homicide in which gems weren't the target.