Since the moment their mother died when Sam and Nate were children Sam has been the one who watched over Nate when their father sent them to a catholic boarding school. It was also Sam that, after a series of bad events that left them wanted by the police, suggested that the two of them change their names from Sam and Nathan Morgan to Sam and Nathan Drake the apparent lost heirs to Sir Francis Drake, the 16th century explorer who, according to the series, had been responsible for discovering El Dorado and the Atlantis of the Sands. Sam was believed dead as is best explained to Elena by Nathan in the chapter called “Hidden in Plain Sight” in Uncharted 4 when he starts to explain why he has been lying about where he has been for weeks by saying “well, for starters this is Sam, Sam Drake. He’s been locked up in a Spanish prison for the last fifteen years because I thought he was killed during a job, but clearly I was very wrong and now he needs to come up with a lot of money or the people that broke him out are going to kill him.” Plot of the game aside Sam is obsessed with the treasure of Captain Henry Avery and leads Nate and by extension Sully out onto the hunt for treasure once again. But Sam’s effect on Nate is different from Sully and Elena’s effects on him. With Sam, Nate finally has someone who can do everything he can, his older brother is a catalyst that instills a competitive drive in him and pushes him to be better if for no other reason than bragging rights since they are so similar.