MacGarrett and Danny finally track down the missing uranium, which has been used to build a bomb located in the middle of the jungle. Now, they must carefully extract the unstable explosive through treacherous terrain ...
When FBI Profiler Alicia Brown finds a body in her bed, she is forced to join McGarrett in the hunt for the chess-piece killer. Also, Kono reconnects with a former surfing competitor, who is now a disabled and homeless war vet
When a cache of guns is stolen from a gun range, Five-0 discovers the culprit is intent on making a dramatic and potentially deadly statement on gun violence. Also, Kono and Adam are finally reunited when he is released from prison.
On Halloween, Five-0 investigates the murder of a medium with a checkered past who was apparently scared to death by a poltergeist. Also, Kono and Adam are kidnapped by what appears to be a death cult.
Five-0 investigates the 10-year-old cold case of a missing teen when a boy suffering from PTSD undergoes hypnosis and realizes he may have witnessed her murder. Also, Danny's sister, Bridget (guest star Missy Peregrym), visits Oahu for a business conference, and he suspects that she may be getting too close to a co-worker.
McGarrett and Five-0 once again become entangled in the twisted mind games of serial killer Dr. Madison Gray when she stumbles into HPD covered in blood that matches Alicia Brown's, and claims amnesia.
MacGarrett and Danny finally track down the missing uranium, which has been used to build a bomb located in the middle of the jungle. Now, they must carefully extract the unstable explosive through treacherous terrain before it detonates.