An obscure character from Star Trek history will finally take the stage. It was announced today that Rebecca Romijn will play Number One in the second season of Star Trek: Discovery at Comic-Con International: San Diego. The news was revealed by Anson Mount, who will also join the series in Season 2.

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Number One is a character who appeared in the unaired pilot for the original Star Trek television series. The character was played by Majel Barrett and acted as a second-in-command for Captain Christopher Pike (Jeffrey Hunter). Pike would eventually be replaced by Captain James T. Kirk (William Shatner) in the second pilot and Number One would become Spock (Leonard Nimoy).

Romijn will play the original character from the unaired pilot alongside Mount’s Pike. Romijn is perhaps known best for her run as Mystique in the original trilogy of X-Men films. More recently, Romijn starred as Eve Baird in the TNT fantasy-adventure series The Librarians.

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Earlier today, the first trailer for the upcoming second season of Star Trek: Discovery was released. The trailer revealed Mount’s interpretation of Pike. Star Trek: Discovery returns with its second season this fall on the CBS All-Access app stateside, on Space in Canada, and Netflix worldwide.