BANG! BANG! BANG! Sam fires shots in the air to break up a fight between a few of the locals and his sailors after one steals a banana. The thief is tossed in the brig with Prosser. Marcus knows he needs the COB's help to find Redman, who has joined sailors Brannan and Cortez on the list of missing crew members. Prosser gives his word that he'll stay in line until he gets the chance to tell his story at a court martial. Marcus gives the order to release the COB.
Julian is ready to kill one of his captives until Cortez persuades him to spend some alone time with her instead. Sophie delays an island escape with her beau to arrange a meeting between Marcus and Julian, who is ticked that a young boy was killed during the firefight that took place in "Blue on Blue." These two leaders each desire something. Julian wants Marcus to bring him the valuable cargo that sits on a boat resting outside the military blockade currently surrounding the island. The missing sailors will be returned if this is done by dawn. Marcus has nine hours.
White House Senior Advisor Amanda Straugh has been named negotiator to the crew of the Colorado. She lets Marcus know that his son will not receive a proper burial until he surrenders. The captain puts his feelings about this situation on hold as the Colorado heads out to sea to retrieve Julian's cargo. The Perseus is activated so the sub can sneak past the blockade. There are some tense moments when the prototype goes offline momentarily, but the cargo is ultimately loaded without a hitch.
The Perseus is eating up power on the Colorado. Marcus gives the order to shut it down. They'll have to return to the island the old-fashioned way by running silent past the blockade. Marcus takes the ship down to dangerous depths to avoid two approaching destroyers as they pass directly above them. Depth charges are in the water. More destroyers are headed their way. Marcus gives the "all stop" order as the ships blow right past them. Time to go back to the beach.
CLANG! A young crewman drops his flashlight. The noise is enough for a destroyer to get sonar lock on the Colorado's position. Marcus orders the sub to head towards an underwater canyon. Their pursuers would be crazy to follow them, as there isn't much clearance. Sophie relinquishes any chance of leaving the island with her beau by heading back to the NATO command center to assist Grace. She's the only one who can help navigate the sub through the canyon walls.
Sophie wants Sam to give her one sonar ping so she can get some bearings. She instructs him where to turn and when. There's not much room in the canyon, but they are almost there. Sam and Sophie work in perfect harmony as the Colorado makes its way through to the other side. These two seem to be forming a special bond. The sub rises out of the water. Unfortunately, the sun also rises. Julian's deadline has come and gone.
Julian wants Cortez to choose which one of them will die. She can't do it. Brannan, on the other hand, offers up Redman. BANG! BANG! BANG! Red is dead. A short time later, Marcus arrives with Julian's cargo. Cortez and Brannan are returned to their captain, who somehow manages to contain his rage even though Julian has executed a member of his crew. Sam and Prosser don't agree on much, but they are both more than ready to avenge Redman's death. Marcus says they will respond to what happened at a time and place of his choosing.
James heads down river with Tani where he meets her family for a traditional island dinner. He witnesses a war of words between father and daughter once Tani learns that her brother has decided to take part in a ritual that will keep him on the island. James follows her into the woods where she's visiting her mother's grave. Tani says her father refused to leave the island even when her mom was sick. She could have been saved if they had gone back to Australia.
Tani and James head deeper into the woods to the place where her brother will one day take part in his ritual. It involves jumping into a stream at the bottom of a beautiful waterfall. Tani takes the plunge. James is right behind her. This is a place where her mother used to take her. It was their little secret, as it was only supposed to be for boys. James moves closer to Tani, who swims away warning that they have a long walk back.
Kylie Sinclair gives Admiral Shepard the file number of the fire order that was sent to the Colorado via the secondary Antarctic network. She then asks her boyfriend, Robert, to get a timestamp on the fire order. A short time later, Robert is visited by an intimidating mystery man. Back home, Kylie exits her shower to discover that her wall safe is open. It's filled with stacks of cash to replace what's been taken. Someone has stolen the only hard drive with all of the tech data for the Perseus prototype. We learn that the mystery man who paid such an ominous visit to Robert is, in fact, Kylie's father.
Cortez only half-tells Marcus what went down at Julian's place. They share a drink at Tani's bar as a funeral procession for the young boy who was killed makes its way through town. Julian is front and center amongst the island people as he locks eyes with Marcus. Sam assures his captain that they will get home to bury his son. There will be 21 guns at Arlington. They'll eventually and ultimately do what is right.