Batwoman is almost ready for her debut.

The CW just revealed the dates for the fifth annual Arrowverse crossover event. This three-night event will mark the debut of Ruby Rose as Batwoman. She'll also star in a pilot for a planned standalone "Batwoman" series.

For this year's crossover, "The Flash" and "Supergirl" will be swapping time periods, for one week only.

• "The Flash" -- Sunday, Dec. 9, 2018 at 8 p.m. ET
• "Arrow" -- Monday, Dec. 10 at 8 p.m.
• "Supergirl" -- Tuesday, Dec. 11 at 8 p.m.

A few months back at The CW's upfront presentation, "Arrow" star Stephen Amell announced this year's big crossover news:

"We are incredibly excited to announce we are doing another crossover event this fall on The CW, and we will be introducing another character in our crossover event. We will be fighting alongside Batwoman."

The CW president Mark Pedowitz confirmed Gotham City will be featured in the Arrowverse, further teasing:

"This will be another full-throttle, action-packed crossover event."

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