In the season finale, we have a complete turn around from the season opener, with Marshall and Lily now Married.
Plot In A Paragraph: At Marshall and Lily's wedding, as the happy couple struggle to find the time to have anything to eat, Barney (The wonderful Neil Patrick Harris) stumbles on to the fact that Ted and Robin are keeping a secret from everyone, and proceeds to spend the entire wedding finding out what it is.
Told mostly in flashback (since EVERY episode is technically told in flash back, this is a flashback in a flashback) we are taken back to something we seen a few episodes back, and are shown what we missed then.
Not a great season finale, but better than the last seasons finale which I did not like. Over all this has been a solid season with some great episodes the slap bet, Swarley, meeting Barney's brother and when Barney went on Price Is Right being particular highlights