Time for a backstory, in the year 2536 Samantha and her little sister Julie were playing in the forest next to there family home in Massachusetts, when Sam and Julie were playing hide and seek, Julie was it and she thought found Sam, but instead she ran into Enclave troopers, and one of them grabbed her, she screamed. Sam heard it and came running to her just in time to see her over an Enclave troopers shoulder as they took of in a vertibird. The Enclave brought Julie to a base on a remote island, they tortured her, wiped her memory, and turned her into a living weapon. But a massive storm was coming and the Enclave evacuated the base, leaving Julie in a cell.
20 Years later

On his way to a mission Rex’s pelican was shoot down, in the middle of the ocean. A few hours later, Rex washed up on the beach of a remote island, he finds a door covered in moss and vines. He prys it open to explore, and realized he was being followed by something invisible. He started fighting the invisible creature, he punched it knocking its helmet off, and he saw the face of a raccoon girl that looked strikingly simlar to his wife Samantha. Knocking off Julie's helmet somehow restored her memory, she remembered being captured by the Enclave, and realized her sister thought she was dead, so her and Rex worked together to fix a communications relay to get rescued, and reunite Sam with her lost sister.

Art and Julie  Rex. Hero of The UNSC
The Enclave belong to Bethesda Softworks
And yes Sam’s last name used to be West