UPDATED: T.J. Miller is in final negotiations to join Kristen Stewart in the deep-sea thriller “Underwater.”

He would also join Jessica Henwick, whose involvement was revealed on Tuesday as well.

Miller stars as entrepreneur Erlich Bachman on the HBO comedy series “Silicon Valley,” which begins its fourth season next month. Miller’s other credits include “Cloverfield,” “Deadpool,” “Office Christmas Party,” and the upcoming “Ready Player One.”

British actress Henwick has credits on “Game of Thrones” as Nymeria Sand, X-wing pilot Jess Pava in “Star Wars: The Force Awakens,” and Colleen Wing in the upcoming Netflix series “Iron Fist.”

Will Eubank, who helmed the sci-fi thriller “The Signal,” is directing “Underwater.” The story focuses on an underwater scientific crew forced to go on a dangerous journey for survival following an earthquake, and is described as an underwater version of Michael Bay’s “Armageddon.”

Stewart would play the lead, a jaded crew member. The studio is planning to start production in New Orleans this month.

Fox-based Chernin is a producer on “Miss Peregrine’s Home for Peculiar Children” and “Hidden Figures,” which was nominated for best picture at the Oscars. It’s also producing several upcoming high-profile Fox titles, including the Amy Schumer-Goldie Hawn action-comedy “Snatched,” franchise entry “War for the Planet of the Apes,” Idris Elba’s romance-adventure “The Mountain Between Us,” and Hugh Jackman’s P.T. Barnum biopic “The Greatest Showman.”

Miller is repped by CAA. Henwick is repped by WME and Julian Belfrage Associates in the UK.