When Nancy’s Valentine’s Day card to Bree is sent to Grace by mistake, Grace thinks they’re best friends.
The chapter begins with Nancy and JoJo delivering Valentine's day cards for everyone on the neighborhood, at this moment she sings Valentine's Day Card, after Nancy finished her song, JoJo wanna give a card to somebody but Nancy told her that she wants to be the one to give all of the cards to her friends that she made. Nancy let Jojo give a small card to Grace but she wanted to give a big card, so Jojo took Bree's card and she gives it to Grace, Grace thinks that she and Nancy are best friends after reading the big card.
After Nancy and Bree meet and then Bree gave Nancy her butterfly card, Nancy goes to give Bree her big card but it went missing. Bree asked Nancy that if she gave the card to someone else but Nancy said that it's impossible and she gave every card to everyone she knows.. Except for Grace. When Grace came by to see Nancy to thank her for the big Valentine card, she called Nancy her best friend and invited her over to her Valentine's Day party at her house. Nancy was screwed that she didn't mean to give Bree's card to Grace because Jojo mixed them up. Bree said it's okay and tells Nancy what she is planning to do with Grace. Since Grace thinks that Nancy is her best friend, she is gonna see Nancy all the time which shocks Nancy.
Nancy imagines how her life would turn out if Grace is her best friend instead of Bree. Grace decorates Nancy's Playhouse with drawings of them together, cuddles with Nancy with two scarves, and stays with Nancy during a third sleepover. This makes Nancy freak out because all of this implies that Grace wants to be with her all the time. But luckily for Nancy, it was just a dream.
Now Nancy knows what she has to do. Nancy has to tell Grace that her Valentine's Day Card is meant for Bree and Bree is her only best friend in order to sort out this problem.
Nancy goes to Grace's house and Grace invited her inside to her party. When Nancy was trying to tell Grace about the letter, she was surprised that Grace's bedroom is so spectacular and Grace put Nancy's Valentine card on her wall. Then Grace opened up to Nancy that she knows that they both don't get along at times but she liked Nancy since her Valentine card implies to Grace that Nancy likes her too. Also, Grace revealed to Nancy that she doesn't have a lot of friends which made Nancy filled with remorse. Grace wanted to be sure that if Nancy is really her best friend so Nancy had to agree to have a drink with Grace. That made Grace so excited that she and Nancy are gonna have a tea party in her honor since Grace knows that Nancy loves tea parties.
Since Nancy said that she can't stay here at Grace's for long because she's going to Mrs. Devine's house for Valentine's Day movie night. Grace said to Nancy that she is going there too so that Grace wanted to show everyone that she and Nancy are best friends. So then, Grace made a toast with Nancy to commemorate their friendship and Nancy had to play along to make Grace stay happy. Nancy nervously smiled and frown as Grace drink her juice.
On the final scene, the kids of the neighborhood are on Mrs. Devine's house for Valentine's Day movie night, before the movie is about to be played, Nancy was hiding from Grace and told Bree that she didn't tell Grace about the Valentine card mixup because she didn't want to hurt her feelings after Grace showed Nancy her bedroom and put her card on the wall. Bree told Nancy to tell Grace what she has to say without being mean as Grace pulled Nancy over to their spot talking about her mom saying that she can invite Nancy over to have hot cocoa after the movie and then the next day, they head to the hair salon.
Nancy had to pause Grace for a moment to tell her the truth but she was nervous to say it. Grace said that best friends can tell each other anything and Nancy feels ready and confident to tell Grace the truth about the letter mixup. When Nancy told Grace that the Valentine Day card she had was meant for Bree after saying it was nice to get to know her, Grace felt sad. Nancy apologized to Grace and told her that she didn't want to hurt her feelings and that Nancy and Bree have been best friends for so long. Grace understood what Nancy meant and opened up again to tell Nancy that she used to have a best friend who gave her valentine cards which is fancier than Nancy's before Grace had to move away. Nancy felt bad that Grace misses her best friend and Grace said that it is okay for Nancy to sit with Bree during the movie.
Since it is still Valentine's Day, Nancy invited Grace to sit with her and Bree while watching the movie. Grace felt that she doesn't wanna get in their way but Nancy insisted that Grace should do it so that way she doesn't feel bad. After hearing what Nancy said, Grace decided to go for it but just this once. As Mrs. Devine finally found the remote, everyone can start watching the movie. As the movie starts to begin, Nancy invites Grace over to sit with her and Bree. Nancy said to Grace Happy Valentine's Day and Grace said the same to her. While Nancy and Bree are enjoying popcorn balls while watching the movie, Grace felt confused and changed about everything she has been through with Nancy.
- In this chapter was revealed that Grace had a best friend before she moved to the Oak Street.
- Grace's house and her respective bedroom makes their first appearance in the series.
- This is the first Valentine's Day special in the series (alongside "Nancy, La Poéte".)