In The Flash's Season 9/series finale, Cobalt Blue (Eddie Thawne) resurrected Eobard Thawne, Zoom, Savitar, and Godspeed in the Negative Speed Force and sent them after Team Flash.
Ultimately, Barry Allen and his friends saved the day—Eddie also saw the error of his ways—before the Fastest Man Alive unleashed a lightning bolt that led to the Speed Force choosing Avery Ho, Max Mercury, and Jess Chambers as new speedsters.
It was a solid send-off for The CW series after a near-10-year run, and Grant Gustin has now revealed some of the changes the finale episode went through.
Appearing at SpaceCon 2025, Gustin and co-star Candice Patton (Iris West), with the former confirming, "We had to change parts of that script." He added, "This was two years into COVID, and I had not gotten it. And I got COVID a week and a half before we wrapped. I kept testing positive, and I couldn't come back to work."
"They shut down for a day or two, and they reworked some of it," Gustin explained "I missed three or four days of filming, at least."
One of the biggest changes came when Gustin was no longer able to reprise his role as Savitar. "I was supposed to be in the scene with the prosthetic scar and make-up, with all the bad guys, when it was Savitar in the suit. That was supposed to be [Gustin] as Savitar. There was other stuff that happened too, my stunt double got some stuff, we shot around him."
So, there were a few hiccups, and looking back on his final day of shooting, Gustin admitted it wasn't the most satisfying of experiences.
"My last day of work was alone on a green screen, which also felt right — like it was kind of heartbreaking," he shared. "I also spent so much time in the suit on green screen, talking to nobody! It felt right, and the last shot I shot was the last shot of the series, Barry running, and pushing it in on him, just looking satisfied, and that was a cool last shot to get."
It wasn't all bad then, but fans were lucky to get a final season at all. The truncated 13-episode season was released at a time when shows like Batwoman and Legends of Tomorrow were being cancelled by The CW as it looked to move away from pricey scripted dramas.
DC Studios co-CEO James Gunn has confirmed he would be open to bringing Gustin into the DCU in a different role. The Flash movie has ensured that the Scarlet Speedster will remain benched for the foreseeable future, and when we do see him again, it will likely be Wally West in the suit.
Were you satisfied with The Flash's series finale?