McGarrett and Danny get Tani Rey to join the task force when a hacker manages to let out a dangerous arsonist from prison.
The stunning truth about a decades-old disappearance of four school boys comes to light when a neurosurgeon is murdered right before a procedure; someone steals McGarrett's car.
The HPD system is hacked and the Five-0's confidential informant is murdered. The team enlist the help of the recently imprisoned hacker Aaron Wright to solve the case.
When Chin and Danny are taken into custody over past deadly transgressions, McGarrett turns to Joe for help.
A dangerous mission to retrieve a bomb containing uranium leads McGarrett and Danny deep into the jungle.