Two Castles is a level in Bowser's Castle in the Bowser Jr.'s Journey mode of Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey.
As Bowser Jr. and the Koopalings head out to the castle balcony, they see the Fawfulized Peach's Castle aroused in darkness, as a result of Dark Bowser unleasing his dark power across the kingdom. Bowser Jr. senses that his dad was in there and heads off to the throne room where the Best Fitness Friends were waiting for him. Roy felt that he could not get over his newly-improved behavior towards the Koopalings, but Ludwig consoles him saying that he seemed genuine in his perspective. Wendy asks the Koopalings about what Bowser had said about keeping Bowser Jr. safe, but Lemmy tells her that he forgot. Wendy flashes back to a moment where Bowser was telling the Koopalings to keep the castle safe while he was heading to Peach's Castle and that he should not have his "blorb things" knock over any of his vases and stuff. He also told the Koopalings to watch over Bowser Jr. while he was gone and that he needed good guidance and wants him to grow up as "strong and wise" as him. The Koopalings did not understand, though Iggy laughs at Bowser, asking if he was joking and that people said that he was "the crazy one", causing Bowser to throw Iggy out of the conversation and asks them as a concerned father to look after him. Iggy, who was on the floor with Morton watching him, replies to himself that even though the moment was inexplicably hilarious, it really hurt to laugh at it. After the flashback, Lemmy asks Wendy if they could take credit for what had happened. Larry tells Lemmy that they should and thinks that Bowser Jr. has handled things all by himself. Wendy exclaims to Larry that helicopter parenting does not always work and that they should just let him run wild. Ludwig replies that there were going to be some speed bumps along the journey. Morton does not know if Bowser Jr. was going to be much wiser in the future. Iggy comments to Morton that his wiseness could be insightful, as Roy replies to them good luck. Bowser Jr., impatiently waiting for the Koopalings to follow him to the throne room, tells them that they have to get going, in which they do, leaving Kamek.