Callen and Sam work with Navy Captain Harmon Rabb Jr to apprehend spies aboard the USS Allegiance; Hetty tries to neutralise a missile attack in the Middle East; Kensi and Deeks are trapped in a mobile CIA unit in Iraq while under attack.
Callen and Sam are aboard a ship that is placed under quarantine for possible Ebola exposure. Kensi and Deeks investigate the murder of a petty officer who recently departed the ship and is linked to the Ebola exposure.
Callen and Sam strive to locate a group of ISIS sympathisers, and Hetty enlists her friend to obtain information from a Russian diplomat.
Alex sends a message to Proctor; Siobhan receives a blast from the past.
Following a lead, Lucas visits a strict Amish schoolteacher who may have insights into the murder of Lana Cleary; transferring a captive Chayton proves more difficult than expected.