The narrator is a time traveler who has gone back in time to save Super Girl from being killed by Reverse Flash with Kryptonite. The narrator first encounters a young version of himself who doesn't believe his story. The narrator then meets Super Girl and explains the situation to her, and they team up to take down Reverse Flash. A battle ensues, and the narrator fights Reverse Flash to save Super Girl.
Here are the key facts from the text:
1. The Reverse Flash killed Super Girl using Kryptonite.
2. The narrator promised Super Girl he would save her, but failed.
3. The narrator is determined to go back in time to save Super Girl.
4. Gary advises the narrator not to try to change the past, as it could cause chaos in the future.
5. The Flash teaches the narrator how to go back in time.
6. The narrator must focus on the past and avoid thinking about school or other events that could cause a catastrophe.
7. The narrator goes back in time to a point before Super Girl's death.
8. The narrator meets a younger version of himself and tries to explain the situation.
9. The younger version of the narrator does not believe the older version.
10. The narrator must run fast to get back to the correct time and place to save Super Girl.
11. The narrator meets Super Girl in the past and tells her about the Reverse Flash's plan.
12. The narrator and Super Girl work together to stop the Reverse Flash.