As usual, it was Sawyer who came up with the funniest line, calling slightly mad scientist Daniel Faraday 'HG Wells' (all that reading must be paying off). In fact, the 100th episode was all about time travel, with Faraday flitting between the Sixties, Seventies and Noughties at an alarming and dizzying rate.
We discovered that he is in fact the son of Charles Widmore/Jim Robinson/Daniel Mead's dad and that his mum is the creepy white-haired woman who played an even creepier ghost in the Nicole Kidman film The Others. (Bizarrely, because of his relationship to Charles Widmore, Faraday is also the half-brother of Desmond's girlfriend Penny, although there appears to be no family resemblance whatsoever.)
Meanwhile back in the Seventies Sawyer had locked up the nasty man who also plays a nasty comedian in Mad Men (one of the perils of appearing in two hit shows at the same time) and was joining forces with the rest of the love quadrangle - Kate, Juliet and Jack - plus Hurley and Miles to get everyone to safety before the impending hydrogen bomb explosion. Faraday tried to warn Miles's dad (scientist Dr Chang) about what was coming, then in a slightly creepy scene he warned the junior version of the red-haired woman he fancied in the future to 'get off the island'. She looked confused and, not surprisingly, more than a little scared.
It then emerged that Faraday's mother was in fact one of the Others (for real), and off he went with Kate and Jack to find her so that she could unlock the secrets of the island. Unfortunately for Kate, Jack and everyone else, his mother, thinking him a deranged intruder, shot him just before the bang of the giant wood block heralding the end of the episode.