Marty opens the door where they heard the rattling sound.
"Blankie, it's pitch dark in this room!"
"I hope you're not thinking of going in."
"No way. We'll just listen for a bit."
They hear the scary sound again from a further corner. And again, a little later, but this time it's louder and coming closer.
"Marty, it sounds like..."
"It's coming towards us, Blankie! Let's run away!"