Uncharted 4: A Thief's End Story
After that we see child Nate at St. Francis orphanage. He was visited by Sam, who had been expelled for criminal activity. Sam tells Nate he's leaving for a job that will keep him away for a few years after helping him sneak out, before cheering him up by telling him he knows where their late mother's belongings were sold.
Years later, the two are on the hunt for infamous pirate Henry Avery. The brothers sneak into a Panama jail where Avery's first mate, Burnes, was hanged, with the help of wealthy treasure hunter Rafe Adler. Nate enters the 300-year-old prison with the help of the corrupt Warden Vargas.
Vargas pulls out a letter and learns that Nate, Sam, and Rafe are on the hunt for Henry Avery's treasure and wants a cut for his help. Nate eventually gains access to Burnes' tower cell and discovers a crucifix. Vargas believes Nate when he claims there are no clues or valuables. The trio finds a safe place to talk, and after discovering that Saint Dismas was the man on the crucifix, they learn that they will be traveling to Scotland next. After that Gustavo came in to fight them and the guard came to finish the fight. There Vargas discovers Nate lied to him. When they are talking for a cut, suddenly Rafe stabs Vargas and try to escape from the prison. Nate and Rafe can manage to escape but Sam was assumed to have been killed in the attempt and because of that Nate gives up on the search.
New Adventure Begins
After fifteen years from the third game, Nate has retired from treasure hunting and now works for a salvage company while attempting to live a normal life with his wife Elena, though he misses the life of adventure. At night he was visited by his brother Sam. He claims, however, that he was freed by his cellmate, drug lord Hector Alcázar, who gave him three months to find the treasure or face his wrath after learning that he doesn't know where it is, contrary to previous statements.
They team up with Nate's mentor Sully and sneak into an auction to steal a crucifix similar to the one in Panama that is being sold at the Rossi Estate in Italy. Nate suggests that they steal the cross in the dark, but that there will be an emergency backup power supply, so they will only have a short time to steal the cross.
Nate goes to meet up with Sam after turning off the lights, with guards on the lookout. After coming back into the building he meets Nadine Ross. Nate is forced to fight alongside Nadine. Nate climbs to the top of a roof, where he finds a cable that he uses to enter the auction room, where he meets up with Sam. The note inside contained Henry Avery's birth and death years, pointing to his grave in Scotland at the Saint Dismas Cathedral burial grounds, indicating that Rafe was always looking in the wrong place, which was the cemetery, not the cathedral itself.
When Nate and Sam arrive in Scotland and sneak past the Shoreline goons, they discover a series of secret passages beneath one of the tombs. After passing some tests, they arrive in a room with a scale, which has another cross on one side and a group of copper coins on the other. Nate sees through the ruse and forces Sam to take one of the coins instead of the cross, which activates a light map pointing to King's Bay in Madagascar. They're then cornered by Nadine, who Sam convinces to spring the scale's trap, causing the chamber to collapse and allowing the two to flee. During this time, Nate begins to suspect Avery of enlisting the help of other pirates for some reason.
The three follow a clue on the coin, which is an engraving of a volcano, to a dormant volcano in King's Bay. They discover inside that Avery, Thomas Tew, and ten other pirates combined their loot into one massive hoard. The next clue to the hoard's location can be found in one of King's Bay's twelve towers. Despite the fact that Shoreline, which arrived first, searches them all, another marking on the other side of the coin narrows the field to just two. Nate and Sully go to the other, which turns out to be the correct one, while Sam goes to the first. Nate realizes where they're going after navigating the various tests.
After that Rafe contacts Nate and reveals that he's been tracking them using their phones' GPS and tries to persuade him to stop chasing them. Nate refuses and saves Sam from Rafe's men after disposing of the phone. Back at the hotel, Nate and Sam tell Sully that the clues point to Libertalia, a remote pirate colony whose Founders appear to be Avery and the other captains. Before they can leave, Nate is confronted by Elena, who has discovered the truth and is furious. When she meets Sam, whom Nate never mentioned, she becomes even more enraged. She flees, and when Nate refuses to abandon his search for her, Sully takes over.
Libertalia
Nate and Sam set out on their own for Libertalia, following more clues on several remote islands until they found the right one. Returning to the beginning of the story, Nate washes up on the island's shore and, after several fights with Shoreline, discovers Sam. They make it to Libertalia together, where they discover evidence of a civil war between the Founders and the colonists following the Founders' theft of all the gold. They learn in the Treasury building that the Founders moved the gold to a walled enclave on the other side of the island called New Devon to protect it.
They're cornered near a cliff by Rafe, who reveals that he was the one who let Sam out of jail; Hector Alcázar had died in a shootout in Argentina six months before. Rafe believes Nate is no longer needed and attempts to shoot him while he is reeling from the deception. Nate is knocked off the cliff despite Sam taking the bullet.
Elena finds Nate alive after changing her mind and enlisting the help of Sully. Nate then tells her the truth about himself: he and Sam were caught stealing their mother's belongings from a large estate by the elderly lady who lived there. When she found out who they were, she revealed that their mother, Cassandra Morgan, worked for her as a historian specializing in Francis Drake. She agrees to let the brothers go, but shortly after, she succumbs to illness, causing Sam and Nate to become concerned because she had already called the cops before learning who they were. They fled with their mother's journal and changed their names to honor her theory about Drake's descendants. From then until Sam's supposed death, they remained together.
Elena agrees to assist Nate in rescuing Sam. When Nate and Elena arrive in New Devon, they discover that the founders have begun fighting amongst themselves. They find the bodies of most of the founders in Tew's house and learn that Tew and Avery poisoned the others in order to keep the treasure for themselves. When they arrive at Avery's house, they enter the catacombs, where they finally reconcile after avoiding numerous traps. They eventually arrive at a shipwreck, where they rescue Sam from Shoreline and Sully saves Nate. Nate appears to persuade Sam to give up, but once they're separated, he changes his mind.
Happy Ending
The three attempt to follow him, but Elena and Sully become unable to do so, leaving Nate to go it alone. He eventually makes his way to the cavern containing Avery's ship and the treasure, where he witnesses Rafe forcing a reluctant Nadine to complete the task. Soon after, a triggered trap detonates on the ship, prompting Nate to dash aboard in search of the treasure and Sam, who is trapped beneath a beam. Despite Rafe's efforts to disarm Nate, Nadine turns on him. She points out the bodies of Avery and Tew, who killed each other over the treasure, and she flees, leaving the three of them on the burning ship.
Rafe, fed up with the Drakes and desperate for the treasure, engages Nate in a sword duel with Avery and Tew's swords, which ends with Nate dropping a net full of gold on top of him, crushing him to death. Nate sets off another explosion, flooding the room and allowing him to free Sam. They rejoin their friends and board Sully's plane.
Years later, Nate and Elena are living on a tropical beachside with their teenage daughter Cassie, and we get the happy ending we seek.