The result of Marge's anger against Quimbys new toll road leads to the discovery of a frozen mailman and his 40-year-old mail. The old mail is delivered to the recipients, including one to Grampa Simpson's deceased wife, and it reveals a secret love affair and who the real father of her baby Homer might be. Confused and emotional, Homer finds Mason Fairbanks, his wealthy and much improved paternal dad, and happily establishes a father-son relationship with him while rejecting Abe, his surrogate father of 40 years, especially after a DNA test reveals that Mason is indeed his real father. Homer joins Mason on an undersea treasure hunt and when Homers life is in mortal danger he reflects upon his childhood and realizes who his true father is. When he confesses that to Abe, Abe has a confession of his own.
The Simpsons focuses on a family of five. There is the father, Homer, a dull-witted, alcoholic, lazy, but lovable man. He often gets his family into crazy situations but always manages to fix things. The mother, Marge, is a stay at home mom who keeps the family together. She is the ideal wife and mother though she can be a little naive at times. She always does what she thinks is best for her family.
Next is Bart, the 10 year old boy who lives on playing pranks. He gets into a lot of trouble but is generally a good kid. Then there is the neglected middle child, Lisa. Lisa is the brain of the family and sometimes feels left out because of that. She is an outcast at school because of her talent. Finally there is Maggie the baby. Though she doesn't say much she is well known especially for her red pacifier.