User blog comment:TDM247/Is Supergirl going to become part of the Universe now or still be a different Earth/@comment-6284741-20160731205346

Wendy Mericle said that it'll be 4 nights one week. Marc Guggenheim said that the Supergirl episode would not feature other characters most likely. The threat across the week will start out that night on Supergirl and then she'll most likely go to Earth-1 to seek help from The Flash, and then end up meeting the Green Arrow and the Legends in the process for the remaining three nights. This is disappointing slightly to me. Whatever they do it should involve Supergirl's Earth merging, and Flash should show up in the Supergirl episode.

As I was typing that last paragraph the thought occured to me. Maybe in the Supergirl episode, "Earth-S" will be acting wierd cuz for some reason it starts to merge and they can't stop it, so at the end of the episode they merge and then "Team Supergirl" meets Team Flash, Team Arrow and Team Legends to deal with, I don't know, maybe Anti-Monitor who caused it or something. I'm not as familiar with DC villains but he does have to do with the multiverse correct?