4. Everything Is A Dream
Mal was right her and Cobb hadnt truly woken up from their first trip to limbo and Cobb is still trapped in a higher up dream level. This explains the various visions Cobb has, as well as being the most tragic theory, having Cobb fully deluded and alone in the dream, unable to wake up and Mal in the real world, all alone. The obvious thing to be dealt with here is the spinning top. We see it topple early on in the film, which taken at face value appears to suggests this is all hokum. However, the top isnt actually Cobbs totem; it was originally Mals. We know from Arthurs possessiveness of his die that each totem is individual, meaning that while it is likely (and cute) that the couple shared or have both used the same totem, it is unlikely they would make such a mistake. Its not too big a leap from here to suggest that because the top isnt his, it can topple in Cobbs dreams. This can lead to a radical reading of the film. If Cobb was trapped in limbo, itd be surprising for Mal not to come down and try and save him, meaning that what is dismissed as a powerful projection could in fact be the real Mal. Obviously theres a few holes, but its a interesting thought and all the more depressing when she fails; Ariadne kills her in limbo, so shell wake up. Of course, this begs the question why we never see her in the top level, making it unlikely.