On summer solstice, Phineas and Ferb introduce their latest idea for a summer day; travelling around the world on a jet plane to make the longest and funnest day of summer ever. Together with Isabella, Kyle Larman, Baljeet, Buford, Candace, Kyle the Otter, Kaytlin, Rudy, Dennis, Cassidy, Kimmy, Wubbzy, Daizy, Widget, Walden, Simba, Nala, Timon and Pumbaa, with Twilight Sparkle, Applejack, Pinkie Pie, Rainbow Dash, Fluttershy, Rarity and Spike following close behind, Phineas and Ferb take off to travel around the world and chase the sun before it sets in Danville. However, everyone doubts that it will work for travelling around the world to chase the sun before it sets in Danville on Summer Solstice is really tough. In addition, Kyle Larman is dealing with problems of his own. But despite this, Phineas believes that it will work.
- Just like in The FT Squad's Adventures With Phineas and Ferb, Simba, Nala, Timon, Pumbaa, Wubbzy, Daizy, Widget and Walden will guest star in this special.
- Additionally guest starring in this special are Twilight Sparkle, Applejack, Pinkie Pie, Rainbow Dash, Fluttershy, Rarity and Spike the Dragon.
- In this special, Kyle Larman suffers from a serious anxiety problem due to struggling to forget a tragic day that occured before, which is why Twilight and her friends are guest starring. They've come to cheer Kyle up.
- The reason why Kyle Larman is suffering from an anxiety problem is because of an event in a DeviantArt story that will happen before this special.
- Princess Celestia will also guest star in this special. She doesn't go with Kyle the Otter, Phineas and the others on their adventure around the world. Instead, she'll be doing something that will make Kyle Larman happy again.