DC's Stargirl: The JSA Realizes Something's Off With Starman in Series Finale Clip (Exclusive)

Last week on DC's Stargirl, fans were stunned with the shocking revelation that Sylvester Pemberton/Starman (Joel McHale) isn't actually Sylvester Pemberton. The episode revealed that instead, the man that Courtney Whitmore/Stargirl (Brec Bassinger) and her allies had gotten close to over the past several months was actually the Ultra-Humanite in Sylvester's body — and now not only does this imposter have control of the Cosmic Staff, but he's buried Pat (Luke Wilson) alive as well. But while viewers are aware of this stunning twist, Courtney and the JSA is only slowly starting to realize that Sylvester told them all some very off things. Now, in a clip from tonight's series finale, "Frenemies Chapter Thirteen: The Reckoning", shared exclusively with ComicBook.com, Courtney and her friends start putting the pieces together.

In the clip, which you can check out for yourself in the video above, each of the members of the JSA realize that "Sylvester" gave them some bad advice: Rick (Cameron Gellman) about the hourglass' limiter, Beth (Anjelika Washington) about pushing away her parents, Yolanda (Yvette Monreal) about Cindy. They start to put together that it was deliberate — and they need to find Pat in a hurry. In addition to the exclusive clip, you can check out the episode synopsis below.

"THE FINAL SHOWDOWN — Courtney (Brec Bassinger) and the JSA find themselves in the fight of their lives against their biggest threat yet.  Luke Wilson, Amy Smart, Yvette Monreal, Anjelika Washington, Cameron Gellman, Trae Romano, Meg DeLacy, Hunter Sansone, Alkoya Brunson and Joel McHale also star.  Walter Carlos Garcia directed the episode written by Geoff Johns."

It was announced last month that the third season of DC's Stargirl would be its last, though series star Courtney Whitmore recently revealed that they filmed two endings in the hope that the series would still get a Season 4 renewal.

"Geoff [Johns] was so smart because obviously there's been a lot of changes in The CW and the Warner Brothers this past year, so the future of any show was not quite certain and because of that, he went the extra mile and shot two different endings, because he did not want to leave the fans with all these question marks," Bassinger said.

"Stargirl has always held a special place in my heart for many reasons. With all the brewing changes at the network, we were aware this was possibly the last season, so we wrote with that in mind and have delivered what I believe to be the best season of Stargirl yet, with complete creative closure," Johns said. "The cast and crew are extraordinary, and I'd like to thank them for helping me bring this series to life. Brec embodied Courtney in every way possible — with grace, strength and humor — exceeding my wildest expectations. I am grateful to WBTV and The CW for giving us a home to tell this story and to honor my beloved late sister, and I'm beyond thankful to the press and fans who have always championed us for three amazing seasons. Most series never get this far. We couldn't be more proud of our show and the fan community it's built!"

DC's Stargirl airs Wednesdays at 8/7c. The series finale airs on December 7th.