Jack Bobridge will go on an insane breakaway, win the stage by an hour and a half, putting the other 160 or so riders outside of the time cut, thus going from 4 hours down to winning the Giro and taking the Points and Mountain Jersey by default.
The way the Giro can be, this almost seems as plausible as status quo right now.
Actually what could just as likely happen is Chaves maintains NIbali on the 2 big climb, then on the descent and 2 km finish, lose about 25-30 seconds, and factor in time bonuses, Nibali down by single seconds going into the final day. Then with the fact that almost no sprinters are left, Nibali and chaves may be sprinting in Tuin for bonus seconds.