Gretel and Bailey are preparing for their special Best Friendaversary Weekend Extravaganza sleepover, when a new student named Tina appears. She and Bailey becomes fast friends, inadvertently shoving Gretel aside. Gretel becomes jealous when Tina is getting all the attention, to the point that she's losing interest in the sleepover. However, it turns out Tina is a spy from the foreign country of Bolgylvania, who has ulterior motives to being friends with Bailey.
Tropes:
- A Bloody Mess: While the truck pushes Gretel against a wall, we see that it looks like blood, but it was actually ketchup from Gretel's ketchup packets.
- Brand X: The game Ocean But With Monsters seems to be a reference to the real-life game Subnautica.
- Does Not Like Spam: Bailey is not much a fan of calzones. After all, they're just folded pizzas.
- Evil Counterpart: Tina is a Bolgylvanian mirror of Gretel. She even has a cyborg gerbil named Gerbil, mirroring Hamster. Ultimately subverted after Gretel brings Tina's own best friend back.
- Floating Advice Reminder: Gretel was struggling how to stop Tina, but luckily, a floating Bailey head advices her to be nice to Tina and calzones are just folded pizza.
- Friend-or-Idol Decision: When Kevin gets a frantic call from Gretel and his phone battery dies before she can finish, he decides to give away his spot on the line to go help her. However, by the time he gets there, the problem is solved, and Kevin apparently misses his chance to get a copy of The Ocean but with Monsters. Fortunately, Roman gives him a special edition copy for his trouble.
- Heel–Face Turn: After Gretel hears her out and reunites her with her best friend Grobla, Tina decides to abort the mission and return home.
- I Just Want to Have Friends: While Tina's mission was to get Bailey's dad to develop a good video game for her country, her interest in Bailey is genuine, because really, she just wanted to have a friend after her own best friend is launched into space.
- Mechanical Animals: Gerbil is a cyborg gerbil, mirroring Hamster being a superpowered hamster.
- The Power of Friendship: Gretel manages Tina to open up by just being nice to her after hearing her floating Bailey head. Hamster and Gerbil patch things out due to this as well.
- Ruritania: Much like how Drusselstein from Phineas and Ferb is a fictional Eastern European country based on East Germany, Bolgylvania is a fictional Eastern European country based on Russia. Unlike Drusselstein, which is stuck in the past even in the modern day, Bolgylvania is a technologically advanced country with a superb class in modern weaponry and a promising, yet failing video game industry.
- Technologically Advanced Foe: Tina's weapons make her stand toe to toe with Gretel and her superpowers.
- Ticket-Line Campout: Kevin camps in front of the video game store so he can buy Roman's latest video game, The Ocean but with Monsters, before it's sold out.
