(SPOILERS FOR BATMAN V SUPERMAN AHEAD)
When you read this, I'm hoping that all of you have seen Batman V Superman and if you were like me or the general audience, you were probably confused by the knightmare Batman has and what appears to be a time travel cameo by a certain speedster. Stop reading right now, if you don't want Batman V Superman to be spoiled for you.
You were probably also shocked by Superman's "death"
The nightmare starts with Batman overseeing an apocalyptic land, later to be kidnapped and killed by an evil Superman who says "she was my world, and you took her from me!" He wakes up and he sees what we assume to be the flash who warns him that "Lois Lane is the key!" and "You were right about him!" The purpose of this is to solely set up the Justice League. The Omega symbol on the ground obviously hints at Darkseid and I believe it sets up the plots for Justice League Part 1 and 2. So....here we go!
Justice League Part 1
At the end of Batman V Superman, at Superman's burial, Bruce Wayne says that they need to assemble a team together due to the possibility that something larger is coming. We've already seen the cameos of metahumans that Lex Luthor and the first hour or first hour and a half would probably just be getting the team together due to the arrival of Darkseid on Earth. While Bruce and Diana are getting the team together, Darkseid manages to get Lois Lane killed and brings Superman back to life and manages to put Superman under his control and by making him believe that Batman or the Justice League killed her. In some interpretations Darkseid is able to manipulate and bring forward the darkness in a person's heart turning them evil, and in Batman's dream, Superman is definitely not good. Ultimately all of this leads to an epic confrontation of Superman and the Justice League and Superman is able to defeat the Justice League but they're able to escape right before he kills them. The world ends up looking like the one in Batman's nightmare and the Justice League now defeated, have to come up with a plan to save the world. They decide to send the Flash back in time and save Lois Lane because Batman remembers the time travel Flash Cameo, but this time the Flash is able to get his message across, and Lois Lane is saved or they take Lois Lane to the future and the movie ends. Either way, Lois Lane sees the future and Evil Superman
Justice League Part 2
At the end of JL 1, Lois Lane is brought to the future in order to stop Superman. They send Lois to Superman and she tries to make him sane and or good again and realize that Darkseid is using him. Darkseid instructs him to kill her and Superman is able to shake free of the mind control and escapes and goes back to join the Justice League. Eventually the Justice League take on Darkseid and his parademons and save the world in an epic hour or longer battle. The world returns back to normal and the world recognizes the Justice League as their heroes.
This storyline is a little vague and there are some details that need to be filled, but if DC pulls of this storyline correctly and well, we're in for some pretty damn good Cinema. Let me know thoughts or possible additions or improvements to the theory below.