Happy birthday, Brandon Routh!

Legends of Tomorrow star Tala Ashe joined Brandon Routh on the set of "Crisis on Infinite Earths" to wish him a happy birthday. Routh, who celebrated his birthday on Oct. 9, will pull double duty when the crossover rolls around this December, playing both Ray Palmer/The Atom and Clark Kent/Kingdom Come Superman.

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Routh won't be the only Superman character in the crossover. Tom Welling and Erica Durance will reprise their Smallville roles for the massive crossover event. Tyler Hoechlin and Elizabeth Tulloch will also appear as Superman and Lois Lane, reprising their roles from last year's Arrowverse crossover. The producers also teased a possible appearance by Nicolas Cage's Superman.

Legends fans will no doubt be pleased to see Ashe on set, as her character was left in a limbo state following the Season 4 finale of Legends of Tomorrow.

"Crisis on Infinite Earths" begins Sunday, Dec. 8 at 8 p.m. ET/PT on Supergirl, then continues in Batwoman on Monday, Dec. 9 at 8 p.m. ET/PT and in The Flashon Tuesday, Dec. 10 at 8 p.m. ET/PT. After the winter hiatus, the crossover will conclude on Tuesday, Jan. 14 in Arrow at 8 p.m. ET/PT and in DC's Legends of Tomorrow at 9 p.m. ET/PT.

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