Voight finds himself at the centre of a murder investigation after a link emerges between him and a prime suspect.
To help his mum, club, and son, Jax works with an unlikely source. Elsewhere, the MC puts Chucky undercover.
When following McGarrett and Wo Fat's escape, gunmen hit Five-0 headquarters. McGarrett must turn on his own in order to find Catherine.
A building collapses during a rodeo; a severely injured cowboy exhibits strange symptoms; Scott causes a serious car accident.
Mike must solve a set of clues to find a 10-year-old witness who knows the location of a drugs stash.