'This Is Us' kicks off season 3! See the very first photo

This Is Us is back at work!

Creator Dan Fogelman marked the start of production on season three on Tuesday with a tease of the very "first scene up." Featuring Sterling K. Brown and Susan Kelechi Watson, the TV couple seemed to be in high spirits in the hilariously candid moment -- with Brown exuberantly celebrating something while Watson had a similar reaction in the background.

"First scene up," Fogelman tweeted. "Season 3 baby!!!"

Mandy Moore couldn't wait to get back on set herself, retweeting the pic and writing on Twitter, "Biggest smile on my face! Love our fam!!" along with the hashtag, "#pearsonpride."

On the eve of season three kicking off, Chrissy Metz shared a reflective post about reuniting with her TV family with a sweet message about what's to come. "Tomorrow we officially start shooting season three of @nbcthisisus! Y’all, it feels like the night before the first day of school!" she wrote on Instagram, opposite an on-set photo from Kate and Toby's wedding in the sophomore finale. "It’s difficult to put into a post what this show and the special humans who make it possible mean to me. I am flooded with emotion and gratitude for each one of you who are as excited as we are to share these new chapters together!"

Just a few weeks ago, Moore and Metz shared teases for what awaits the Pearson family in the new season, posting photos of their reactions to the script of the drama's anticipated premiere episode, which is written by co-showrunners Dan Fogelman, Isaac Aptaker and Elizabeth Berger, and will be directed by Ken Olin.

"Reading the first episode of #ThisIsUs season 3... is NOT for the faint of heart," Moore wrote on her Instagram story looking emotionally drained and with red, puffy eyes.

"Just read our season 3 premiere episode on the flight home... The flight attendant asked if I was okay... still not sure," Metz wrote, alongside a GIF of a kid looking distraught and the word "Feelings."

Back in May, Moore hinted to ET that parts of the This Is Us series finale may have already been filmed, even though there has been no indication as to when the show will end. “I don’t know!” Moore teased. “Maybe parts of the ending have been shot." She assured fans that the series finale is still “a ways off,” adding that the cast knows “there’s a finite amount of time that the show will exist.”

Moore revealed that she and her castmates were already ready to get back to work on season three.

“We were just standing back in the green room, and Dan started telling Chrissy and Sully [Chris Sullivan] and Milo [Ventimiglia] and I a little detail about season three and we are all like, ‘What?!’” she said at the time. “We want to know everything too and we are so excited, but the sit down, sort of walking through what happens throughout the course of this season probably won’t happen until a couple of weeks from now when we are closer to shooting.”

This Is Us returns Tuesday, Sept. 25 at 9 p.m. ET/PT on NBC.