Sunset never really had the time or the interest in dating ponies. She's the worst when it comes to talking about emotions. When she finally comes to the conclusion she likes Silverspeed, she freaks the heck out.
After seeing more of her classmates getting their own cutie marks, Dinky and Apple Bloom both get discouraged by their own lack of cutie marks. The two both agree to search for their cutie mark despite their family members reassurances.
When Twilight's portals release Tirek into the human world and the humans get turned into ponies, they have to unite with their ponyselves to defeat him and save both world's.
Sunset as the rest of Equestria is looking forward to the summer sun celebration until the main attraction goes missing and Sunset is determined to get her back.
Lyra and her crew help Starlight and Trixie as the two other unicorns discover a plot to destroy Equestria. The humans turned ponies work to save one of their own.
Amethyst Star (also known as Sparkler) is a unicorn who lives in Ponyville. She's the librarian for the Golden Oaks Library, and loves to read. But when she reads about the possibility of a huge threat to Equestria, she's not one to just sit idly by.
This is the story they never wanted to tell you. This is the story about your favorite characters that has been kept secret. This is the story... behind the laughter.
"I believe a light will pierce the darkness and drive it away. I believe that someday we'll be able to laugh again under the clear blue sky. And I believe that Amethyst Star will be that sparkling light." [GUYVER PONIFICATION BEGINS]
The PPP is a secret oganization tasked with keeping Equestria safe. No pony knows who they are; their agents blend into the background just like any other pony. With their expertise, keeping the unicorn Twilight Sparkle safe should be no problem.