Following is a transcript of the video. Narrator: In the "Black Mirror" episode "San Junipero," Yorkie and Kelly meet and fall in love in a virtual afterlife. And in this world, the possibilities are ...

As long as people have been alive, they've wanted to stay alive. But unlike finding the fountain of youth or becoming a vampire, uploading your brain to a computer might actually be possible.

NARRATOR (JACK FORTUNE): This is the story of the man behind the most remarkable discovery. His breakthrough seemed so revolutionary it could have created an extraordinary new world. A world where ...