The summary is about Princess Luna, who is having trouble with a monster made of blue smoke that is invading the dreams of her friends, including Twilight Sparkle. The monster was created by Luna's own guilt and negative emotions, which have given it strength. The monster's goal is to escape into the real world and turn Equestria into a nightmare.
Twilight Sparkle and her friends try to help Luna by creating a shared dream where they can confront the monster together. However, the monster proves to be too powerful and it becomes clear that the only way to defeat it is for Luna to forgive herself and let go of her guilt.
With the help of her friends, Luna is able to forgive herself and weaken the monster, saving Equestria from becoming a nightmare. The story concludes with Luna feeling grateful and relieved, and her friends celebrating their victory.
Here are the key facts extracted from the text:
1. The main character has a dream about a monster made of blue smoke.
2. The main character writes a letter to Princess Luna about the dream.
3. Princess Luna explains that the monster is a creature from her own nightmares.
4. The creature escaped from Princess Luna's dreams and is now infecting the dreams of others.
5. The creature becomes stronger with each new dream it infects.
6. If the creature gains enough strength, it will be able to escape into the real world and turn Equestria into a nightmare.
7. Princess Luna is the only one who can move through the kingdom of sleep and stop the creature.
8. The main character and their friends come up with a plan to help Princess Luna catch the creature.
9. Princess Luna creates a common dream for all the ponies in Ponyville to share.
10. The creature feeds on feelings of guilt and becomes stronger when Princess Luna feels guilty.
11. Princess Luna created the creature as a way to punish herself for past mistakes.
12. The creature's strength is tied to Princess Luna's guilt, and when she forgives herself, the creature becomes weaker.
13. The main character and their friends help Princess Luna to forgive herself and stop the creature.