River Heights' new ice cream store, Jim and Barry's Ice Cream Factory, will be celebrating opening day on Saturday with an ice cream flavor contest. The prize is ice cream for a year. Eight-year-old Nancy Drew and her friends George Fayne and Bess Marvin intend to enter the contest with a blueberry, vanilla and surprise ingredient recipe.
The three girls make a batch of the ice cream in Nancy's yard. Fellow classmate Deirdre Shannon is writing about the contest on her website and wants to taste their ice cream. The ice cream isn't ready, so Nancy invites Deirdre to go inside the house to get some lemonade and oatmeal cookies.
Another friend, Kendra Jackson, is going to enter the contest, too. She wants to know what these three friends think of her ice cream. When Deirdre comes back out, Deirdre agrees not to post Kendra's recipe, so Kendra gives her a taste, too. Everyone is impressed by Kendra's chocolate ice cream flavor.
At the kick-off event on Thursday, Nancy, George and Bess sign up for the contest and then get their free samples of ice cream. Kevin Garcia comes for the free ice cream samples. His parents own a health food store in town, and the family diet doesn't include foods like ice cream, candy or other sweets. Daisy Dorfer and members of the Jim and Barry Fan Club she founded come to sign up for the contest, but they are still deciding on a recipe. Deirdre attends to take pictures to go with her story. And Henderson Murphy, the son of local ice cream truck owner Chuck Murphy, briefly appears to heckle and picket.
Kendra writes down her recipe and brings it with her for the ice cream owners to autograph, but the recipe goes missing. Kendra included the flavor name on the recipe, but not her name as the creator of it. Kendra asks Nancy, George and Bess to find the person who took the recipe. The three girls agree to take the case. Deirdre takes a picture of them.
Back at Nancy's house that afternoon, the girls brainstorm. They think Daisy might be a suspect, but don't think Kevin would be since his parents don't let him have sweets. The girls check on their ice cream. When Nancy drops the container, the girls go to the store to buy ingredients for another batch.
At the store, the girls are surprised to see Kevin buying a basketful of chocolate products. Daisy and the fan club members have decided on a recipe and are shopping for ingredients. Deirdre has posted on her website that the trio are on the case.
When Nancy goes outside that night, she finds the words "Give Up" spelled out in Popsicle sticks on her front steps. The next morning, Friday, Nancy tells George and Bess about the message and shows them the Popsicle sticks. The sticks have a distinctive company name imprint.
Nancy doesn't think Kevin bought enough Popsicles at the store to make the message with the sticks but wonders if Deirdre and the fan club members might have. The three girls decide to go to a club meeting and try to join to find out the club's ice cream recipe. During a taste test, the club members learn that Bess doesn't like one of Jim and Barry's ice cream flavors and won't let them join. As the girls leave, George sneaks out a piece of paper from the writing pad Daisy wrote the club's recipe on.
The girls do a pencil rub on the paper and are able to read the fan club's ice cream recipe. It is not chocolate. Nancy looks at the Popsicle stick she still has from her taste test, and it does not have an imprint like the one she found on the sticks left on her front steps.
When the girls ride their bikes to get smoothies, they see Kevin leaving a chocolate shop. They ride their bikes to the ice cream factory to see if Kevin signed up for the contest. The guard in the lobby won't let the girls look at the sign-up list or talk to the owners. When the guard gets a phone call, the girls sneak in and end up in a room filled with ice cream vats. The company owners find them. The owners don't let them see the contestant list, either.
In the lobby once again, the girls notice a new guard on duty and convince him to let them look at the sign-up list. Kevin's name is on the list. The trio bikes to Kevin's house, and they find him hiding in the shed. His parents said he could buy anything he wanted with his birthday money, so he bought sweets — including Popsicles. Kevin tells Nancy, George and Bess he was going to enter the contest with a chocolate flavored recipe, but he ate all the chocolate instead. He thought if he won the prize, he would be able to eat all the ice cream he wanted.
Kevin's Popsicle sticks don't have the company imprint Nancy found on the sticks on her front steps, either. As the girls walk back to their bikes, Nancy hears the ice cream truck. She sees a boy buying an ice cream bar and asks to look at the stick. It has the same company imprint as the sticks she found on her front steps. Nancy, George and Bess wonder if Henderson wrote the message, but since he didn't enter the contest, he doesn't seem like a logical suspect.
Saturday morning, the three girls meet at George's house to go to the contest. Nancy sees a box of menus for an event George's mother is catering that day, and Bess reads one. The dessert is chocolate ice cream, and it has the same name that Kendra gave her ice cream recipe. George's mother tells the girls that the mayor requested the ice cream for his birthday party after someone delivered a sample of the ice cream to his house the day before.
Nancy, George and Bess go to the mayor's house to ask him about the ice cream. Since the contest is less than 30 minutes away, the girls take their ice cream with them. On the way, Kendra joins them. The mayor tells the four girls that the ice cream came from the ice cream truck owner, Henderson's father. Henderson rides by on his skateboard; the girls chase him but don't catch up to him. Deirdre roller skates by and is able to stop Henderson. He admits to Nancy, George, Bess, Kendra and Deirdre that he left the Popsicle sticks on Nancy's front steps. He found the recipe on the ground outside Jim and Barry's Ice Cream Factory the day of the contest sign-up and kick-off, thought it sounded good and gave it to his father. Kendra examines her backpack and finds a hole in it.
Kendra asks Deirdre not to write about the incident, and she agrees. Henderson tells his father that Kendra came up with the recipe. Henderson's father gives Kendra ice cream bars he made with her recipe to enter in the contest.
The ice cream company owners like the fan club's flavor and Kendra's flavor, but neither wins. Nancy, Bess and George's ice cream melted, so they didn't win. Kevin came up with a yogurt-based dessert, and he wins the contest. Henderson's father keeps Kendra's recipe title for the ice cream bars he created from her recipe and adds Kendra's name to the title. Deirdre takes a picture of Kendra in front of the ice cream truck for her website. Nancy, George and Bess are sad they lost the contest, but glad they solved the case.