Summarize the plot of Deltarune Chapter 1.
Deltarune Chapter 1 is a role-playing video game developed and published by Toby Fox. The game is set in a mysterious, alternate dimension called Deltarune, and follows the story of a young human named Kris who is transported there after falling through a hole in their school's basement. Once there, Kris is greeted by Susie, a mysterious girl who acts as their guide, and together they set out on a journey to save the land of Deltarune from an impending darkness.

Throughout the course of the game, Kris and Susie explore the various regions of Deltarune, meeting a cast of unique and colorful characters. They battle against various monsters and bosses, and collect items and weapons to aid them in their quest. Along the way, Kris discovers that they have the ability to wield the power of light, which allows them to vanquish the darkness and restore light to the land.

As the game progresses, Kris and Susie begin to uncover more about the true nature of Deltarune and the darkness that threatens it. The game ends with a cliffhanger and leaves the story open for the next chapter.
What happens in the next chapter?