Right, so the catalyst for the second Back To The Future is that Biff messes up the entirety of history by half-inching a sports almanac, car jacking the DeLorean, and sending himself back to 1955 where he gives his younger self the book of results and instructions to make millions through placing bets. Then that causes a dark alternate 1985 where Biff is Marty's abusive step-dad who somehow runs the world from a dystopian casino lair, and he's forced Lorraine to get a boob job because the Oedipal complex wasn't confusing and icky enough for everyone involved as it was. Except, having created that alternate timeline, Biff has thus eliminated the 2015 where he stole the almanac and time machine in the first place. He changed the future, with Doc locked up in an asylum and Marty supposedly off in the Swiss alps or whatever. So he couldn't have returned the DeLorean to Marty and Doc in 2015, for them to travel back and realise the timeline had been tampered with: the 2015 Old Biff went back to would have been similarly dark and dystopian. And his messing with the timeline would mean he never had the chance to go and break stuff in the first place. Head hurt yet?
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/
