Anna's nineteenth birthday

Anna's nineteenth birthday took place on the summer solstice and was celebrated with a party set up by Elsa.

Prelude
Due to their separation in childhood, Elsa missed many of Anna's birthdays while growing up. Following their reconciliation during the Great Thaw, Elsa planned to give Anna a memorable birthday and spent weeks planning for the event.

Preparations


On the day of Anna's birthday, Elsa, Kristoff, Sven, and Olaf were busy with the final preparations for the party in the courtyard. While Elsa anxiously pondered over a selection of ice figurines to top off Anna's birthday cake, Kristoff and Sven erected a large banner bearing the words, "HAPPY BIRTHDAY ANNA". Though she was anxious, Elsa left Kristoff in charge of the courtyard so that she could rouse Anna and start off the day.

Scavenger hunt
Sneaking into Anna's room to find her still in bed, Elsa nudged Anna awake and informed her about a special day she had prepared for her. After Anna sprang up from her bed and got dressed, Elsa used her magic to add color and pattern to both their dresses, then instructed Anna to follow the string for a scavenger hunt.

Accompanied by Elsa, Anna followed the string through a hallway as Elsa led her to checkpoints where presents were hidden. Inside a suit of armor, Anna found a bracelet. Inside a cabinet was a cuckoo clock in a shape of Arendelle castle with a pop-out Olaf. Next, the string led the sisters to a balcony, where there was a bouquet of flowers on its railing. As Elsa lowered herself and Anna to a lower floor of the castle, Anna found a sandwich in a basket suspended by the string. The two sisters bounced off a couch, finding a portrait of them with Olaf, Kristoff, and Sven on a wall at the apex of their jumps. As they biked through another hallway, Anna's face caught a stocking that was suspended by the string above the hallway. The scavenger hunt continued as the sisters exited the castle.

Heading into the village, Elsa led Anna to a wooden boat, where they picked up a fishing rod. Next, they gathered a snow globe and a cloak from Oaken's Cloakens. Elsa then conducted a children's choir to sing for Anna. After collecting a sparkling party hat, Elsa led Anna up a clock tower, where there were wooden dolls of the two sisters. The scavenger hunt would culminate with a surprise party at the castle courtyard.

Elsa's cold
Prior to the scavenger hunt, while waiting for Anna to get dressed, Elsa sneezed. Hearing the sneeze, Anna worried that Elsa might have a cold, only for Elsa to deny such. As the sisters spent the day collecting the aforementioned presents, Elsa exhibited signs of a cold through her constant sneezes. At each sneeze, little mischievous snowmen called Snowgies were conjured. Though the snowmen went unnoticed by the sisters, Anna was concerned for Elsa's condition, despite the latter's assurance otherwise. The pair continued their scavenger hunt as more Snowgies continued to materialize with Elsa's deteriorating condition.

The growing horde of snowmen became a hindrance to Kristoff, Olaf, and Sven in the courtyard. Initially asleep, the trio was awakened by the presence of the Snowgies who made Anna's cake their delectable target, prompting the three to defend the cake from the rambunctious snowmen. At one time, the Snowgies destroyed the "HAPPY BIRTHDAY ANNA" banner, and Olaf volunteered to fix it, but being illiterate, he arranged the letters to read "DRY BANANA HIPPY HAT". Later, the letters were rearranged to "HAPPY HAIRY ANT BAND".

As Anna and Elsa headed into the village, they encountered Oaken, who offered Elsa a cold remedy. Though Elsa turned down the offer, Anna accepted the medicine. As the sisters continued on to the clock tower, Elsa became more feverish, causing Anna's concern to grow further. However, her fears were confirmed when Elsa deliriously climbed up the tower and nearly fell after spinning round a wooden beam. After being saved by Anna, Elsa acknowledged that she had a cold, and the sisters made their way back to the castle. Though Elsa brooded over how she had ruined the day, Anna assured her sister otherwise and remained focused on getting her to bed for some rest.

The party


At the courtyard, Kristoff, Sven, and Olaf continued to defend the cake from the Snowgies; however, the snowmen ceased their assault upon seeing Anna and Elsa arrive. They subsequently arranged themselves in a way that Kristoff was able to leap from the mass of snowmen and slide onto the ground to present the cake to Anna, who admired the spectacle. Elsa, now realizing that the Snowgies were the results from her sneezes, saw that the surprise party she had worked hard for Anna was a rousing, spectacular success. After the cake was distributed to the party guests and the Snowgies, Anna insisted her sister to go to bed, but Elsa forced her way to blow a birthday bukkehorn. Anna tried to persuade Elsa not to exert herself any further, but Elsa managed to grab the horn and sneezed into it, causing a giant snowball to launch from the horn and soar away from Arendelle.

Conclusion
After the party concluded, Anna helped a very exhausted and very feverish Elsa into her bed. Feeding her bedridden sister some warm soup, Anna lovingly remarked that her best birthday present was being allowed to take care of Elsa.

Meanwhile, Kristoff traveled to the North Mountain with Sven and Olaf to deliver the Snowgies to Elsa's ice palace to live with Marshmallow, who had taken up permanent residence in the structure.