"How I Met Your Mother" season 9, episode 21 airs tomorrow night - find out where to watch online a free live stream of "How I Met Your Mother" season 9, episode 21, titled "Gary Blauman." There are only two episodes left of "HIMYM"!

If you can't make it to a TV by 8pm EST tomorrow night to catch "How I Met Your Mother" season 9, episode 21, click here to watch "Gary Blauman" online via a free live stream!

If that doesn't work, CBS also offers episodes on their website to watch online the morning after an episode airs.

The synopsis for "How I Met Your Mother" season 9, episode 21, titled "Gary Blauman," reads: "When Gary Blauman shows up minutes before the wedding is about to begin, it sends the gang into a frenzy as they each recall an encounter with him."

Taran Killam will guest star as Gary Blauman in tomorrow's episode, while Wayne Brady will return as Barney's brother James, Hollywood Hills reports.

The promo video reveals that Barney and Robin will lose it when they see Taran Killam's character Gary - Barney punches holes in the walls, and Robin has a meltdown! This episode is sure to send the gang into "Code red!" mode before the wedding begins.

Fun fact: Cobie Smulders (who plays Robin) is married to Taran Killam! They married in September, 2012 and have a daughter together.

Catch "How I Met Your Mother" season 9, episode 21 on Monday night, March 17 at 8/7c on CBS.