Jess is hired to be a zombie at a haunted house; Cece and Schmidt accidentally wear perfectly matched costumes; a former college crush visits Nick and expresses her affection in an alarming way.
The team gets a new lead in the mole investigation after an unknown assailant kills two men disguised as sheriff's deputies in front of Callen's home; Nell interviews a prison inmate who has information on the department's leak.
When a college student dies at a dinosaur show, the CSIs must determine if it was murder or an accident.
Beverly discovers Murray is actually a year younger than they knew, so she plans a do-over at celebrating his 50th birthday; Coach Mellor attempts to prepare Adam for pickleball tryouts.
Geoff struggles to keep his living arrangement with Erica and Barry a secret from Beverly during game night; Adam goes to his guidance teacher for a lesson in being cool, so he can get closer to a new girl in chemistry class.
