Stranger Things is back, baby! And it's truly one of the most chaotic seasons yet.

Now, six months after the Battle of Starcourt, the gang will return to take on their biggest threat yet: high school. Hopper is still missing, the Byers family moved away, and Eleven is still struggling without her powers. Oh, and there's the Upside Down, of course. With a new villain on our hands, we'll watch as our favorite characters put an end to the Upside Down once and for all.

So, to celebrate Stranger Things' fourth season, below are some photos of the cast in their first big role vs. in the series vs. IRL:

1.Millie Bobby Brown in her first big role as Young Alice in the Once Upon a Time spinoff series Once Upon a Time in Wonderland in 2013:

Here's Millie as Eleven on Season 4 of Stranger Things:

And here's Millie in real life:

2.This is Finn Wolfhard in his first big role as himself in the music video for "Retro Oceans" by Facts in 2012:

Here's Finn as Mike Wheeler on Season 4 of Stranger Things:

And here's Finn in real life:

3.This is Gaten Matarazzo in his first big role as Gavroche in Les Miserables in 2014:

Here's Gaten as Dustin Henderson on Season 4 of Stranger Things:

And here's Gaten in real life:

4.This is Caleb McLaughlin in his first big role as Noah in Noah Dreams of Origami Fortunes in 2012:

Here's Caleb as Lucas Sinclair on Season 4 of Stranger Things:

And here's Caleb in real life:

5.This is Noah Schnapp in his first big role as Roger Donovan in Bridge of Spies in 2015:

Here's Noah as Will Byers on Season 4 of Stranger Things:

And here's Noah in real life:

6.This is Sadie Sink in her first big role as Lana on The Americans in 2013:

Here's Sadie as Max Mayfield on Season 4 of Stranger Things:

And here's Sadie in real life:

7.This is Priah Ferguson in her first big role as Asia on Atlanta in 2016:

Here's Priah as Erica Sinclair on Season 4 of Stranger Things:

And here's Priah in real life:

8.This is Charlie Heaton in his first big role as Jason Waycott on Casualty in 2015:

Here's Charlie as Jonathan Byers on Season 4 of Stranger Things:

And here's Charlie in real life:

9.This is Natalia Dyer in her first big role as Clarissa Granger in Hannah Montana: The Movie in 2009:

Here's Natalia as Nancy Wheeler on Season 4 of Stranger Things:

And here's Natalia in real life:

10.This is Joe Keery in his first big role as Emmett on Chicago Fire in 2015:

Here's Joe Keery as Steve Harrington on Season 4 of Stranger Things:

And here's Joe Keery in real life:

11.This is Maya Hawke in her first big role as Jo March in the BBC miniseries Little Women in 2017:

Here's Maya as Robin Buckley on Season 4 of Stranger Things:

And here's Maya in real life:

12.This is Joseph Quinn in his first big role as Arthur Havisham on Dickensian in 2015:

Here's Joseph as Eddie Munson on Season 4 of Stranger Things:

And here's Joseph in real life:

13.This is Eduardo Franco in his first big role as Stu on Gamer's Guide to Pretty Much Everything in 2015:

Here's Eduardo as Argyle on Season 4 of Stranger Things:

And here's Eduardo in real life:

14.This is Winona Ryder in her first big role as Rina in Lucas in 1986:

Here's Winona Ryder as Joyce Byers on Season 4 of Stranger Things:

And here's Winona in real life:

15.This is David Harbour in his first big role as Officer Shanks on As the World Turns in 1999:

Here's David as Jim Hopper on Season 4 of Stranger Things:

And here's David in real life:

16.This is Brett Gelman in his first big role as one of the various characters he played on Human Giant in 2007:

Here's Brett as Murray Bauman on Season 4 of Stranger Things:

And here's Brett in real life:

17.This is Paul Reiser in his first big role as Modell in Diner in 1982:

Here's Paul as Sam Owens on Season 4 of Stranger Things:

And here's Paul in real life:

18.Finally, this is Jamie Campbell Bower in his first big role as Anthony in Sweeney Todd: The Demon Barber of Fleet Street in 2007:

Here's Jamie as Peter Ballard / One / Vecna on Season 4 of Stranger Things:

And here's Jamie in real life:

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More on this

• The "Stranger Things" Cast Is All Grown Up — Here's What They Looked Like In Their First Seasons Vs. NowAngelica Martinez · June 1, 2022

• Everyone Is Obsessed With "Dear Billy" From "Stranger Things" Season 4, Especially The Last Five MinutesNora Dominick · May 31, 2022

• Sadie Sink Talked Meeting Taylor Swift, Millie Bobby Brown Shared Her Least Favorite Stunt, And So Many More Secrets From The "Stranger Things" CastLauren Garafano · May 27, 2022

• These Pictures Show How Everyone From "Stranger Things" Seriously Transformed From Season 1 Vs. Season 4Matt Stopera · May 16, 2022