Since the first season of The Flash, Eobard Thawne (Reverse Flash) has been a constant thorn in the side of Barry Allen and his team, as he's the man who killed Barry's mother. The two enemies will have another showdown in the show's upcoming season finale, entitled "Legacy."

Released earlier today by the CW, the synopsis for the episode reveals the plot will center on the Fastest Man Alive once again doing battle with his greatest nemesis, though it doesn't detail what Thawne does this time to incur Barry's wrath.

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In this season, it was revealed that Barry and Iris' daughter from the future, Nora, had secretly been working with an older, incarcerated version of Thawne to help her father capture the anti-metahuman serial killer Cicada.

Though Thawne seems to legitimately care about Nora, fans of the show know all too well that nothing is ever what it seems with Thawne. So, whatever Thawne does to start up another fight with Barry, chances are good that it's something to once again bring tragedy into the Scarlet Speedster's life.

"Legacy" will air May 14. Check below for the synopsis:

THE FLASH

Legacy-(8:00-9:00 p.m. ET) (Content Rating TBD) (HDTV)

BARRY FACES OFF WITH REVERSE FLASH-Barry (Grant Gustin) faces off with his oldest, and most formidable nemesis, Reverse Flash (Tom Cavanagh). Gregory Smith directed the episode with story by Lauren Certo and teleplay by Todd Helbing & Eric Wallace (#522). Original airdate 5/14/2019.

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Airing Tuesdays at 8 p.m. ET/PT on The CW, The Flash stars Grant Gustin, Candice Patton, Carlos Valdes, Danielle Panabaker, Tom Cavanaugh, Jesse L. Martin, Danielle Nicolet, Hartley Sawyer and Jessica Parker Kennedy.