Three SEALs from McGarrett's former unit have been killed, revenge for a mission 16 years earlier in Morocco. An assassin attempts to kill McGarrett in his home but crawls away after being stabbed. McGarrett won't involve HPD but wants to do an off-the-books mission with just Five-0. McGarrett and Joe plan their own mission, to hook up with Cole, the only other member of the squad still alive. McGarrett confronts Greer, to accuses her of setting up the attacks. Adam is going to recruit a prisoner, Gakuto, to figure out with whom Greer is talking. McGarrett and Joe head to Joe's remote ranch. Grover captures Bauer, the man who tried to kill McGarrett. Cole shows up at the ranch, bearing weapons, but Joe already has an armory. They set up for a siege. Gakuto points Adam to a guard, but that guard has already broken out Greer. Cole gets shot in the first wave of attack. McGarrett goes out to rescue Cole, but a missile kills Cole and knocks McGarrett for a loop. Tani tracks down the group behind the attack. Grover gets Bauer to cooperate by promising to get him to a German prison, so his family can visit him. Bauer gives up the name of the lawyer who hired him. One by one, McGarrett and Joe take out the attackers, although Joe is shot and badly injured. McGarrett calls Five-0 for help. Omar Hassan, the son of the target the original mission took out, is behind the attack. Their vehicles are shot up, so they ride horses to go to the nearby house of a surgeon. Joe fooled Steve. He just wants to go to a favorite spot to die, under a tall tree. McGarrett recalled how Joe set him on the right path after Steve stole a car at 16.