About this "The Simpsons" episode:
The Simpsons - Homer's Paternity Coot is the 10th episode of season 17 and number 366 overall in the series.

Marge's protest against a toll booth causes an accident at the Springfield Tire Yard (which has been perpetually on fire since the 80s), melting a frozen section of a mountain and revealing the corpse of a mailman who has a letter from Homer's mom, who had an affair with a handsome lifeguard who may be Homer's biological father.