We watch “The Big Bang” (Series 5, Episode 13) where the Doctor ping pongs around in time attempting to get to the bottom of Amy’s crack. Whilst attempting to solve said mystery, Amy becomes undead, Rory never bothers shaving, a Dalek gets stoned, River Song gets ‘Groundhog Day’ed and the Doctor tries to make ‘fez’ happen. Stop trying to make ‘fez’ happen Doctor! Anywho…the Doctor manages to reboot the entire universe by blowing up the Tardis. But the Tardis blowing up created Amy’s crack which caused the universe to blink out of existence requiring the Tardis to be blowed up…? Oh the timey wimeyness of it all!