Watch Hawaii Five-0 Season 9 Episode 21 Online. Best and Free Online streaming for Hawaii Five-0 TV Show. We picked the best sites to stream s09e21. Simply pick a site below and click "Watch Now!" button next to it. Some of the links may be broken, please upvote the working and good links so other users see those links for Hawaii Five-0 Season 9 Episode 21 s09e21 at the top of the list.