Binge-watch "Gateway to the Unknown" today: watch "Making Frozen 2" online at Disney Plus. It's a behind-the-scenes look at the biggest animated film ever made, and a welcome return to Arendelle, or at least to the talented people who voiced the cast and created the scenery.

Into the Unknown: Making Frozen 2 is a six-episode documentary about how the sequel to "Anna and the Snow Queen" was made, from storyboarding to songwriting to recording to animating key scenes. The film begins with only about 11 months to go before its scheduled theatrical release, meaning that only about 20% of the film is complete. Stressful!

In "Anna and the Snow Queen 2," Elsa, Anna, and friends embark on a journey beyond the Kingdom of Arendelle to discover the origin of Elsa's magical powers.

Into the Unknown: Making Frozen 2 is an interesting, in-depth look at Disney's production process, especially the tricky sequences. The first three episodes focus heavily on the big Act III musical number "Show Yourself" and how it initially went awry. The series also reveals how Disney relies on the brain trust of animated filmmakers to provide feedback. Directors and screenwriters from "Wreck-It Ralph," "Moana," "Zootopia," "The Little Mermaid," and others watch rough cuts of films and offer candid critiques of what worked, what didn't, and what could be improved.

There are also very emotional moments involving the voice cast, such as when Kristen Bell discusses how the song "The Next Right Thing" helped her deal with her own depression and anxiety.

Disney Plus is becoming a home for fascinating making-of documentaries. This spring, the streaming service released Disney Gallery: The Mandalorian, which took fans behind the scenes of the hit live-action Star Wars series (including how Baby Yoda came to be).

Here's everything you need to know about how to watch Into the Unknown: The Making of "Frozen 2"

"Into the Unknown: Making Frozen 2" is today, Friday, June 26, on Disney Plus. Disney Plus exclusively distributed the film today, June 26 (Fri.). Of course, Frozen 2 is also available on Disney Plus.

Take a peek at the documenaries on how the "Anna and the Snow Queen" team created the highest grossing animated film of all time.