When Nathaniel Upshore touches someone who has died unnaturally he experiences (in seconds) an alternate life in which that person is a part. Sometimes, nothing happens; their eyes meet across a crowded room, and that’s it. He can’t help them. But sometimes they meet, fall in love, and grow old together. And if at the end of that alternative lifetime he truly loves that person, then he can bring them back. He retains the memory of that lifetime, but they do not share the experience. In ‘Another Life,’ we see the aftermath of Nate’s saving of Samantha Kincaid. As a result of his intervention, he loves her deeply, and hopes she might have some memory of the life he remembers sharing with her.