Captain Sonny Jennings and his core team of lifeguards monitor the dangerous Hawaiian waters; new lifeguard recruits compete to join Sonny's district; Sonny and his family grieve after the loss of his nephew; Em reveals a romantic past with Will.

Em works to earn the team's respect when she is left in charge and Hina and Kainalu juggle multiple beachside emergencies; Will's fiancee pays him a visit at work; Sonny opens up to a former lifeguard about his trauma since losing his nephew.