Super Crossover Planned for December for Flash, Supergirl, Legends of Tomorrow and Arrow

I'm hoping it is called Crisis on Infinite Earths.

The CW announced that its four DC Comics superhero shows will come together for a special crossover episode in December.
CW President Mark Pedowitz alluded to the idea of the universes of Arrow, The Flash, Legends of Tomorrow and the newly acquired Supergirl coming together in a crossover which he called "our biggest ever."
"Just imagine what our superhero crossover episode is going to look like come December," he said.

Have them face the Anti-monitor and Barry has to give his life to save the universe. It would be a great cliffhanger and a way to bring all the universes together into one. Then have Flash be the search for Barry to see if they can bring him back from the dead.