Marge: I'm worried about the kids, Homey. Lisa's becoming very obsessive.

Marge: I'm worried about the kids, Homey. Lisa's becoming very
obsessive. This morning I caught her trying to dissect her own
raincoat.
Homer: [scoffs] I know. And this perpetual motion machine she made
today is a joke! It just keeps going faster and faster.
Marge: And Bart isn't doing very well either. He needs boundaries and
structure. There's something about flying a kite at night that's
so unwholesome. [looks out window]
Bart: [creepy voice] Hello, Mother dear.
Marge: [closing the curtains] That's it: we have to get them back to
school.
Homer: I'm with you, Marge. Lisa! Get in here.
[Lisa walks in, chuckling nervously]
In this house, we obey the laws of thermodynamics!
-- The last straw, "The PTA Disbands"