When a Marine corporal dies in a tide pool after being exposed to fentanyl, the NCIS team must quickly find the source of the drugs; Alex talks to his parents about taking a gap year; Ernie reveals personal news to Lucy.
Junior and Tani track down the thief who robbed his parents' home; Five-0 investigates the murder of a beloved philanthropist and the theft of his valuable koa tree; Danny moves in with McGarrett.