Death Stranding EXPLAINED: All Ending Questions Answered
7. Who Is Amelie?
The Last Stranding is Amelie's grand plan, and her allegiances are also a recurring thread throughout the game. The entire story kicks off because Sam wants to save his sister from apparently being held captive. He couldn't give two s**ts about America, but this personal connection is enough to get him on the journey. This motivation is strengthened even more because it comes just after the death of Sam and Amelie's 'mother', Bridget.
After freeing her, it's revealed the whole set up was manipulation on Amelie's part to get Sam where he needed to be, and put into action The Last Stranding. She reveals that Amelie and Bridget are essentially one in the same. 'Bridget' is the being's 'Ha' (essentially the human body, a vessel that lives, breathes and ages on Earth), while Amelie is the 'Ka' (the soul, which exists only on her Beach).
This explains why nobody has actually seen Amelie, why she only communicates via hologram, and why she never ages (which is brought up right at the beginning and everyone just goes with it).
Why does she want to bring life to an end, though? Well...