"Wow, smarter than I thought. Look, it's your lucky day cause I was just passing by when you two kicked it. I can help you guys with the whole...you know, being dead thing." She grinned at them. They looked gullible enough to trick someone into saying her name. 

"Alright, here's the deal, I'm a demon. So whatever I do, I can't effect the world of the living but you two can. I can help you guys be ghosts. Whatdaya say?"