Carter is putting money in a birthday card for Chris at Mort's pharmacy.  

He has Cleveland mail the card for him even if he's not in uniform. He delivers the card to Chris. Chris opens the card and sees that he only gave him a dollar. 

Brian is drinking again. The story is all about how the dollar Carter gave Chris travels from character to character.

Peter goes to the Clam and plays a drinking game with Quagmire. He changes his dollar for 100 pennies. Lois meets with Peter's chicken and then his wife Nicole. They fight. The dollar eventually gets to Seamus. 

Carter tells Chris the dollar was rare and he and Chris go off on a quest to find the dollar.

Stewie takes Brian to a drug den to buy him some drugs to get him off the booze.  A shootout ensues. The dollar is picked up by a rat and it ends up back at the Clam.

The rat gets out and gets a lift from Mayor West and the dollar gets picked up by Seamus again (with his number on it that he gave to Meg.)

Seamus takes the dollar to the Clam and talks to Jerome. Mort's kid get s the dollar from Jerome. Meg checks with Seamus about their date. The dollar ends up on Peter's driveway. Bonnie picks it up and tells Joe about it. The dollar ends up back with Seamus and Meg.

Seamus and Meg are on a date at a club where Ida is singing with Ryan Reynolds playing at the piano.

Brian admits he couldn't go for a day without drinking. Seamus puts the dollar in Ida's tip jar. She takes it to a strip club when Chris and Carter come in and find the dollar, but before they can get it it gets mixed up. They turn off everything except the blacklight and find the dollar which is worthless now because it has Seamus' number on it.

Every character on the show takes a selfie together.