For many people, summer is just getting started.

Youve had your Fourth of July barbecue, and now youre ready for some serious beach or pool time.

But for Hollywood, its already time to get back to work.

THIS IS US; Riverdale

Credit: Ron Batzdorff/NBC; Shane Harvey/The CW

On Monday, some of televisions hottest stars were back on set to resume production on their hit series.

Cant believe were starting season 4, she wrote.

It wasnt only Mendes who got to lay around on the job their first day back.

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In his post, he included a shirtless photo of titular character Archie Andrews (K.J.

Apa) and captioned it: And were back.

Second day of shooting #Riverdale Season 4 along with an assortment of emojis.

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The cast ofThis Is Us, meanwhile, is back to work on the Paramount lot in Hollywood.

Pearson matriarchMandy Mooreand patriarchMilo Ventimigliashared posts on their social media accounts straight from the lot.

Prep today/film tomorrow #HereWeGo.

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This Is Usreturns Sept. 24 on NBC, whileRiverdalereturns Oct. 9 on the CW.

A premiere date for the new season ofWill & Gracehas yet to be announced.

This article was originally published July 8, 2019, and most recently updated July 11, 2019.