The Flash season 3 will premiere Tuesday October 4th at 8pm on The CW, Arrow season 5 will premiere in the same timeslot on Wednesday October 5th, Supergirl season 2 on Monday October 10th, and Legends of Tomorrow season 2 on Thursday October 13th.
“It’s an external threat from outside the shows that will involve Supergirl coming over to The Flash, then Arrow, then Legends of Tomorrow.”
Now, new insight from Arrow and Legends of Tomorrow executive producer Marc Guggenheim confirms Kara Danvers (Melissa Benoist) will be a connecting thread of the crossover.
It seems this year’s crossover will be a combination of both these structures, offering individual stories for each series that will tie together in an overarching narrative.