LONDON — Rhys Ifans and Ed Skrein are to star in science-fiction thriller “Gateway 6.” Altitude Film Sales will handle worldwide sales and introduce the project to buyers at the American Film Market, which runs Nov. 4-11 in Santa Monica.

Malachi Smyth’s screenplay topped the most recent Brit List, which is a compendium of stellar unproduced scripts by non-U.S. writers, set up to complement the U.S. Black List. Scripts that have made the Brit List in previous years include “The King’s Speech,” “My Week with Marilyn” and “The Best Exotic Marigold Hotel.”

The project is the feature debut of director Tanel Toom, whose short “The Confession” was nominated for an Academy Award in 2011.

The movie “combines the solitary abandonment of ‘Moon’ with the claustrophobic atmosphere of ‘Das Boot,’ and the fight to survive instincts of ‘Alien,’” according to Altitude.

Set in the future, on a war-ravaged Earth, four soldiers man the last bastion Gateway 6 — an outpost in a sea-covered continent — awaiting a relief crew or the enemy, whichever comes first. But as the empty weeks turn to months, paranoia descends that tests relationships to breaking point. Especially with the arrival of a deserted boat — was it the help they’d been so anxiously waiting for, or something far more sinister?

Ifans, whose credits include “The Amazing Spider-Man” and “Notting Hill,” is soon to be seen in Oliver Stone’s “Snowden” and James Bobin’s “Alice Through the Looking Glass.” Skrein has been in “The Transporter Refueled” and “Kill Your Friends,” and has just completed a major role as lead villain Ajax in “Deadpool,” opposite Ryan Reynolds.

“Gateway 6” is due to shoot in Estonia in spring 2016 and is produced by Ben Pullen of Sentinel Entertainment and Matthew James Wilkinson (“The Call Up”) for Stigma Films, with Pippa Cross serving as executive producer. Ivo Felt, producer of the Oscar-nominated foreign language title, “Tangerines,” will be co-producing.

Pullen said Toom and Smyth have “created a unique and scarily authentic glimpse into the future which allows for an intensely claustrophobic sci-fi thrill ride set against a vast sweeping canvas.”

Mike Runagall, managing director of Altitude Film Sales, said, “Recalling classic 70s sci-fi, ‘Gateway 6’ is a smart and ambitious contained thriller set in a unique and fully realized world that is by turns, thrilling, surprising and emotional with a palpable sense of humanity at its core.”

Ifans is represented by 42 and UTA, and Ed Skrein is represented by 42 and CAA. Further casting will be announced before the AFM.