A poster on Reddit appears to have released information regarding the 2016 Suicide Squad movie. If the information is correct, then Warner Bros. is working with multiple story situations, one of which we find to be quite similar to the 2014 animation Batman: Assault on Arkham.
The movie may have the same pattern as a time-sensitive conflict where the Suicide Squad must locate bombs placed in and around the city by the Joker and his cronies. These bombs are set at a time, and must be defused before they go off, which would cause a massive catastrophe.
Naturally, Amanda Waller does not want this to happen, so she enlists the Suicide Squad, making Harley Quinn a member of the team because she knows how the Joker thinks.
During this era, Harley has been estranged from the Joker, and if Assault on Arkham is anything to go by, we may already have an idea why they have separated in the first place.
"What we were given mentioned Harley Quinn being needed to decipher a complex series of bombs planted throughout Gotham," posted a Reddit user. "Harley is estranged from The Joker, and her knowledge is being used to figure out where The Joker has placed the bombs. Deathstroke is Amanda Waller's personal bodyguard, and he's placed in the squad to oversee that they do not deviate from the mission perimeters. The plot then becomes more complex as The Joker has a far more complex goal in mind.
The big surprise here is that Deathstroke is the personal bodyguard of Amanda Waller. We find this difficult to believe, so maybe this Reddit user made a mistake and meant Deadshot instead.
Some aspects of the other plots include Lex Luthor working with The Joker, and another that places Harley Quinn in a position to betray the Suicide Squad in order to aid The Joker.
As mentioned above, the plot details sound similar to what have been done in Batman: Assault on Arkham. We'd love to see the film go down this route; however, there is no need to allow Lex Luthor to have a broad hand in what The Joker is doing.
The Joker is a mad man, and Luthor should be less than willing to work with him unless he is completely desperate after the events that will take place in Batman v Superman: Dawn of Justice.