For four days, Jack tries to call Bunny—unsuccessfully. She keeps hanging up on him.
When she finally answers, she tells him that she knows a secret about why her dad is buying all the abandoned Norvelt houses. And she'll clue Jack in if he meets her that night at 10:00, while she is doing her Girl Scout fire patrol (to make sure the Hells Angels don't burn down any more houses).
So, Jack escapes through the coal chute in the basement, and puts on his handy Grim Reaper robe, although this time without mask.
Bunny is waiting for Jack—and smoking. (Uncool, Bunny!)
It turns out that Mr. Huffer is selling the empty Norvelt houses to the other town to expand his business. Since there are more people in Eleanor, he wants to move his business to make more money. Like Jack's dad, he sees Norvelt as a dead end.
Apparently, the Hells Angels agree: they've been sneaking into town and starting small fires, which is why Bunny is on fire patrol.
And here comes a Hells Angel right now to burn another house down. When he confronts Jack and Bunny, they run off into the night.
Got to say, that sounds like a good move.
Bunny blows her emergency whistle, and the fire department shows up to put out the blaze.
The house is saved, and so is Jack—his mother doesn't discover that he's been out of the house.