Homer, where are you going? Work. It's 4 o'clock on a Saturd...
(Marge is suspicious of Homer, who is wearing a fedora hat and a trench coat.)
Marge: Homer, where are you going?
Marge: It's 4 o'clock on a Saturday.
Homer: I, uh, have to... count the atoms at the nuclear plant. Conservation of mass! It's the law!