Castle and Beckett investigate the murder of Will Medina, the assistant curator of the Natural History Museum. The Museum's personnel believe his death is related to the curse of the ancient Mayan tombs.
Patrick investigates the identity of a woman with amnesia who stepped in front of Van Pelt and Cho's car. Hightower issues Rigsby and Van Pelt with an ultimatum.
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.
Buffy and Giles become suspicious of a Peruvian exchange student, with whom Xander falls in love.
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.