The team investigate when a cab driver and his passenger are found dead. Elsewhere, McGarrett helps his sister to spy on her shady neighbours.
The team is tasked with a covert mission to infiltrate a Boko Haram camp, hack its data network and rescue an American hostage.
When a gang identifies and executes an undercover agent, the team must locate a mole before other agents are put in danger.
Magnum investigates the death of a hotel guest who was thrown from her room's balcony while working on a secret investigation of her own. Icepick is released from jail and is trying to keep a secret from Rick.
When newly-engaged Penny learns that Pete wants to elope, would-be wedding coordinator Jane takes the lovebirds and the rest of the gang to a wedding.