According to May and the EU negotiations are over. Some people think the EU will reopen negotiations if we ask them nicely, after parliament votes against May, or after a general election perhaps, others think the EU will not re-negotiate at all, or will not agree substantial changes at any rate. If the latter are right some people think the Act of Withdrawal obliges us to to leave the EU with no deal, whilst others think we should tell the EU we've changed our mind and want to stay, and if we ask to stay some people think the EU will say too late we've agreed you're going, others think they'll say ok mates carry on as you were, while still others think they'll say if you want to stay you'll have to accept new conditions, like joining the Euro and Schengen. I wouldn't waste too much time working it out yet though, because in December you can watch May and Corbyn explain it all on telly, unless you want to watch I'm a Celebrity instead. Which might not be a bad idea when I think about it.