Some mail is unfrozen after 40 years after Marge's protest against a toll booth damages a lot of tires that end up at the Tire Fire. One of the letters was for Mona from her lifeguard lover, who could be Homer's biological father.

!! Tropes:
* FemaleGaze: Mona is seen staring at the lifeguard's backside in a photowith Abe.
* KarmaHoudini: Kent Brockman publicly read a letter addressed to Mr. Largo and is never seen being punished for it.
* MamasBabyPapasMaybe: Homer isn't sure if his real father is Abe Simpson or Mason Fairbanks.
* MyLifeFlashedBeforeMyEyes: Homer experiences it near the end and finally remembers the good moments he spent with Abe Simpson.
* TheScrooge: Everyone who'd rather take "The Ol' Cheapstake's Trail" than pay the toll.
* SpecialGuest: Michael York as Mason Fairbanks.