Next Chapter Issues

In writing the newest chapter of my story I decided to use my OC, who happens to be best friends with Chrysalis and Cadance's long-lost big sister, to help with the Nightmare Moon issue. Thing is, I can't think of what to actually write after Princess Eclipse Star gets to Canterlot and has to tell the guards not to attack Chrysalis. I'll be posting what I've written so far in Chapter 4 soon so somepony can help me figure out what the heck to write. Darn I hate writer's block!! Yeah so blind OC, Queen Chrysalis, Nightmare Moon, Princess Queen Luna, and Princess Celestia. Those are the mane characters in my story.