Picking up where the season three finale left off, we find McGarrett and Wo Fat cornered by unknown assailants in a detainment facility. McGarrett gets the drop on the aggressors and kills all but one, Ricardo Cosi, who he drags back to Five-0 headquarters for interrogation. While there, the building is stormed and taken over by armed members of the NLM, and their decision to target innocent hostages forces McGarrett and Danny to turn Cosi over to them. Instead of leaving with Cosi, however, the gunmen execute him, then turn themselves over to the cops. McGarrett senses that something is off as the NLM gunmen are loaded into a transport vehicle, and he quickly gets a call from El Condor, the leader of the NLM, who informs him that Catherine is being held hostage. El Condor will guarantee her safety if McGarrett orders the release of the NLM gunmen immediately. McGarrett complies, much to the dismay of SWAT commander, Captain Grover, and the NLM gunmen make their getaway. When Sgt. Lukela informs them that a news chopper was reported stolen in the morning, Five-0 figures out that the closest open landing zone would be in Aloha Stadium, and the team races to intercept the NLM before they can get off the island. After a shootout in the stadium parking lot and intense aerial combat between McGarrett and El Condor, Five-0 manages to kill or subdue all of the escaping criminals.Meanwhile, Kono and Adam head for Hong Kong on a shipping vessel, with Chin Ho keeping an eye on them via satellite and GPS. Later, the Five-0 team is dismayed to learn that the NLM gunmen stole data from Five-0 headquarters during their siege and transmitted it to an unknown third party. Data which detailed Kono and Adam's most recent location.