When people die, they go directly to the afterlife, or at least they're supposed to. You see, Josie Saltzman has been dead for a year, yet she's no closer to leaving. As The Necromancer explains it, someone is holding onto her spirit too tightly. He makes a decision to partially release his control over her, just enough that her spirit is free to go to the person that's holding onto it. That's how she ends up appearing out of thin air and falling into a partially pained canvas in Hope's room.