The Grey's Anatomy firehouse spin-off is rounding out its cast!

Deadline announced on Friday that Hamilton alum Okieriete Onaodowan, Grey Damon (Aquarius), Danielle Savre (Too Close to Home) and Barrett Doss (Marvel's Iron Fist) will be joining Grey's grad Jason George and Rosewood's Jaina Lee Ortiz on the new series.

The spin-off will focus on a firehouse in Seattle and will launch with a backdoor pilot on Grey's Anatomy this fall. The untitled drama will then return for its 10-episode first season in 2018. So far, George is the only Grey's cast member making the switch to the new series, but fans should expect plenty of crossover between the two shows.

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Production on the new series was delayed one week, according to Deadline, to allow the cast to be fully fleshed out. Grey's executive producer Stacy McKee will be overseeing the new series which is also executive produced by director Paris Barclay, and Shondaland's Betsy Beers and Shonda Rhimes.

Grey's Anatomy continues Thursdays at 8/7c on ABC.