Grant Gustin reveals he got COVID in last days of filming The Flash series finale

The Flash is bringing back an entire rogues gallery of villains in the series finale. From the Reverse-Flash (Tom Cavanagh) to Zoom (Teddy Sears) to Godspeed (Karan Oberoi) to former ally Eddie Thawne (Rick Cosnett) turning to the dark side, Barry Allen (Grant Gustin) definitely has his hands full with foes. But the titular superhero faced one more unexpected and unscripted battle when series star Gustin got COVID in the final days of filming.

"I didn't get COVID for three years, and we were six days away from finishing and I somehow got COVID," Gustin tells EW in our latest cover story. "And God bless them, they somehow made it work and shifted some things around on the schedule. We shut down for a day. I was just so close to the finish line and ended up having to do the full 10-day quarantine because I was just still testing positive. And I felt fine! I just had to sit at home and wait to do my last few days for a while."

Colin Bentley/The CW Grant Gustin as the Flash

There's never a convenient time to get sick, but Gustin still can't believe how he ended up getting COVID in the home stretch of filming the finale. "It's a pretty inconvenient time for everybody's sake, but they did do a really good job of making it work," he adds.

While Gustin was in quarantine, production continued as best as it could without its star. "There was some creative filming that had to be done and they were going to have to add him in later," Danielle Panabaker says. "They were going to have to shoot some of his stuff to add on green screen."

Ultimately, another day had to be tacked on to the schedule to finish out Gustin's scenes — while most of the cast wrapped on a Friday, he had to return to film on Saturday. He also had to be written out of one scene in particular (which he calls "disappointing" for a reason he can't reveal before the finale airs). But once he finished quarantining, he went back to work immediately.

"I had recovered by the time I was filming, but it was killing me," Gustin says. "Everyone wrapped before me because of that! Candice [Patton] and I shot a really important scene together on Friday, she had her very emotional finish, and I was really happy to be there for that. It was a really special moment. And then the next day was a Saturday that we had to add of all the green screen work."

He laughs before adding, "It felt like they were trying to keep me here. We just prolonged the end."

The Flash series finale airs Wednesday, May 24, at 8 p.m. ET/PT on the CW.

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