Ricky awakens Saturday morning and telephones Grace Foster to ask her if she can give him a discount for some pearls he wants to buy Lucy as an anniversary gift. When Lucy walks in, Ricky pretends he is talking to Sam. She goes to fix Ricky's breakfast while he gets dressed. Ethel enters and wonders why Lucy is cooking rice for breakfast. Lucy explains that she is trying to drop hints to remind Ricky of their anniversary on Monday. Ricky comes into the kitchen to have his breakfast as Lucy tries pulling out all the stops to remind him of their upcoming anniversary, but he keeps mum about it, and makes a hasty retreat to Grace Foster's apartment, under the pretext of going to see Fred. Moments later, Fred shows up looking for Ricky. Lucy tells him that Ricky had just gone looking for him. Fred arrives some time later and says that no one is in the apartment, so Fred heads back to look for Ricky. Ricky arrives soon explaining that he'll talk to Fred later since he seemed to be busy with the painters (they are painting the building). Fred comes in a few moments later and tells a confused Lucy that he never saw or spoke to Ricky.
Ethel returns to the Ricardos' kitchen with news that she saw Ricky coming out of Grace Foster's apartment. Lucy assumes Ricky is talking to Grace's husband Bill, but Ethel tells her that he's out of town. Thinking of the implications of Ethel's news, Lucy's imagination gets the best of her and she bursts into tears.
At the club, Ricky rehearses with the band and gets a message from Jules ("Julie") that Grace Foster had called and wants him to come over to the apartment. Ricky assures Julie that it's just business. Later on at the apartment, Fred arrives asking Ricky what he wanted. Ricky explains that he simply used Fred as an excuse to go to Grace Foster's apartment to look at some pearls for Lucy. As Lucy enters-giving Ricky the cold shoulder since she thinks he's forgotten their anniversary-Fred exits. Grace Foster calls and Ricky beats Lucy to the phone. She goes to the other room and eavesdrops on the other line while Ricky and Grace talk business, but she thinks they're having an affair. Ricky heads down to Grace's apartment (again under the pretext of going to see Fred). Ethel comes in and Lucy tells her what she just overheard on the phone. The two try to come up with a way for Lucy to see what's going on at Grace's and end up downstairs in the basement listening through the furnace. The girls are able to hear what's going on not only in Grace's apartment, but the apartment in 4B as well. Lucy and Ethel then don painters' overalls and go out on the scaffold to peek into Grace's apartment. While lowering the scaffold, Lucy ends up with a bucket of paint on her head and covered in paint. Fred and Ricky help the girls into the apartment and Lucy demands an explanation. Ricky almost leads Lucy to believe that he and Grace were planning on running away to Mexico to live happily ever after, but he lets the cat out of the bag and tells her that he's just bought her a string of pearls as her anniversary gift. The couple kiss and Ricky gets paint on himself.