The Flash showrunner reveals how Tom Cavanagh returns in series finale: 'Always part of the plan'

Barry Allen's (Grant Gustin) story can't end before he faces his greatest enemy one last time on The Flash.

EW can exclusively reveal that Tom Cavanagh is returning to the CW's last Arrowverse show in the series finale as Eobard Thawne, a.k.a. the Reverse-Flash. The actor broke the news of his own return to the series back in February, but showrunner Eric Wallace tells EW that his appearance in the May 24 episode, "A New World, Part Four," will be as his original season 1 villain.

Jack Rowand/The CW Tom Cavanagh returns in 'The Flash' series finale as Eobard Thawne, a.k.a. the Reverse-Flash

"This is Barry Allen's final race, so you can't tell that story without including his most infamous adversary: The Reverse-Flash," Wallace told EW prior to the writers' strike. "And having brilliantly played the character since season 1, bringing Tom back as our show concludes its run was always part of the plan. Tom's exciting portrayal of Eobard Thawne has been unforgettable for nine years, and fans will be delighted to know that he's brought that same wonderful intensity to our finale, too."

Last seen in season 8, Eobard Thawne is a brilliant scientist from the future who was obsessed with becoming a hero just like the Flash. But after gaining super-speed of his own, his jealousy over Barry Allen's prominence drove him to become the Flash's greatest enemy.

The Flash airs Wednesdays at 8 p.m. ET/PT on the CW.

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