Marty and Rat are child ghosts and Rat is like a leader controlling his friends. When Marty said something, Rat frowned at him saying "Who dialed your number?"
Is Who dialed your number? an idiom to mean "You told you to speak?"? I've never heard of this, but it seems so. It it is, it's so funny.
Marty- He's rat. I'm marty. And victor's hiding somewhere. That's what he does.Rat- Who dialed your number?
Marty - Sorry, rat.
RAt - How come you can see us?
Melinda - Um, it's a gift i have. I was born with it.Some gift.