The team tracks an arsonist through a radical environmental group that uses fire to spread its message.
One of Patrick Jane's former clients (Kelli Williams), Beth, asks for help when her son is kidnapped; Patrick clashes with Beth's new spiritual adviser.
After the passing of a family friend, the Ottos all react differently to the allotment of the deceased's inheritance.
Gibbs and Kate suspect the CIA may be involved in the demise of a Navy officer, and believe that an espionage expert's work could lead them to the killer.
The team must probe an unusual murder case while thinking of the best way to say farewell to the late Detective Frost.