Tristen MacDonald

A patient's desire to end her life triggers haunting memories for Hunt; Arizona and Callie have different opinions about the future.

After an ambush changes the course of their investigation, the NCIS team has to quickly find answers, and one team member flashes back to their very first NCIS assignment.

Callum undertakes a tough undercover assignment when an NSA agent disappears while tracking a dangerous ISIS cell.

Callen is placed in a tough situation when his father is linked to a terrible case of radiation poisoning.

The team uncovers a sinister connection when a grad student who's inventing a high-tech weapon for the Navy is attacked.

A promising student wakes up to the hangover from hell when he is found wandering the streets covered in blood and wielding an axe. As the investigators attempt to piece together the night's events, Flack struggles to keep his cool and Mac develops a bond with the suspect.