As this week's episode of Heroes resurrects Arthur Petrelli, long thought to be dead, we look at the general idea of characters coming back from the dead, how they are introduced in the show, and how they change the relationships of the existing characters. Interviewed are Cristine Rose (Angela Petrelli), Adrian Pasdar (Nathan Petrelli), Milo Ventimiglia (Peter Petrelli) and Jack Coleman (HRG).