Mario & Luigi: Triple Trouble is a game for the Nintendo Wii U. It involves Mario and Luigi teaming up with Bowser to save the world from the evil Galaxy Ztar. With the aid of old friends such as Starlow, the Mario Bros. and Bowser take a journey to destroy the Galaxy Ztar.
Story isn't in chapters in-game, but it is a way to organize the plot.
A long time ago, dark energy ruled the galaxy. Every one of these combined into the Galaxy Star, which turned instantly into a black hole.
1000 years later, we found out what happened when a black hole dies.
The game clips over to Mario, Luigi, Peach and Daisy camping, on a mountain. The Beanbean Kingdom can be seen in the distance. Suddenly, a purple lightning bolt strikes, and the tents are fried. The heroes go to check it out. Right before they do, Bowser comes in, crying, with the Koopalings and Bowser Jr. seen flying away. Bowser says his castle was blown up by some dark energy. While talking, the Mario Bros. notice Peach and Daisy are missing.