When Sirius gets his hands on a time turner, he manages to send himself, James, Lily, and Remus to the future.
It's the year 1993 when Remus takes up the job as Defense Against the Dark Arts professor. It's Harry Potter's third year at Hogwarts, and Sirius Black is on the loose. Nymphadora Tonks is an Auror-in-training, assigned with the mission to protect The Boy Who Lived. Disguised as a student, she tries to figure out the mystery that is Remus Lupin.
It is impossible to know how life after death is. Where do they go? How is it? Do we really see those we have lost before? We cannot experience something without actually being there.