Glee went to a legendary place this week, as How I Met Your Mother star Neil Patrick Harris played a key role on the episode.

Meanwhile, next Tuesday, simply put, Glee will go Gaga.

As earlier reports have confirmed, the cast and crew went "all out" for "Theatricality," which focuses on a number of Lady Gaga hits - and costumes. We absolutely cannot wait!

It looks like there's a monumental life moment ahead for Rachel, too. Watch the following Fox promo and see what we mean:

[video url="http://www.tvfanatic.com/videos/theatricality-promo/" title="Theatricality Promo"] [/video]

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.