'Batman v Superman: Dawn of Justice' is guaranteed to be one of 2016 - if not the decade's - biggest movies.

So it's understandable that there's a fair amount of fan speculation about what will happen when two of comic and moviedom's biggest superheroes smackdown.

But there's one Batman v Superman: Dawn of Justice fan theory currently blowing up (the nerd part of) the internet that is either utterly bonkers or insanely inspired genius. It's thousands of words long, so for those suffering from a mighty case of TL: DR, here are the cliff notes...

Brace yourselves, things are about to get a leeeetle controversial...

Christopher Nolan's 'The Dark Knight 'trilogy is part of the new Zack Snyder DC cinematic universe. 'Man of Steel 'and 'Batman v Superman' are set 'after' the events of The Dark Knight Rises.

Ben Affleck isn't playing Bruce Wayne. He is playing Slade Wilson - AKA Deathstroke- who has taken on the role of Batman.

Christian Bale will pop up as a surprise supporting character, reprising his role as Batman.

Jeremy Irons isn't playing Alfred.

Jared Leto's Joker (who will be seen in' Suicide Squad') is a former Robin who has been driven mad. He is actually playing the same character as Joseph Gordon-Levitt's John Blake/Robin character from 'The Dark Knight Rises'.

Superman's psychotic clone Bizarro will also appear.

They'll use existing 'The Dark Knight 'footage to bring back Heath Ledger's Joker.

POTENTIAL SPOILER INSANITY ENDS

So, yeah. Bit mad.

There are a thousand counter-arguments that could be made, and it's debatable as to how much trust you should place in a writer who can't spell correctly, but it's also hard to deny it's a pretty well-thought-out (if elaborate) theory.

We'll have to wait until 'Batman v Superman: Dawn of Justice' hits UK cinemas on 25 March 2016 to find out for sure.