Nick Shakoour

Chin and Abby are faced with a difficult decision, and McGarrett gets word that someone is plotting to launch a terrorist attack on Oahu.

Callen and Sam work with Navy Capt. Harmon Rabb, Jr. (David James Elliott) to apprehend spies aboard the USS Allegiance. Also, Hetty partners with Marine Lt. Col. Sarah "Mac" Mackenzie to neutralize a missile attack in the Middle East, and Kensi and Deeks are trapped in a mobile CIA unit in Iraq while under attack by ISIS.