Watch the Trailer for Christopher Nolan’s WWII Epic Dunkirk

The trailer for Christopher Nolan’s World War II film Dunkirk leaked online Thursday, a day ahead of its official announcement.

The clip, which is only 30 seconds of the minute-long trailer, was taken on a mobile device at a movie theater, according to Vanity Fair. Warner Bros. quickly removed the pirated clips from YouTube and released the official trailer.

The official Dunkirk trailer was set to be released Friday alongside the movie Suicide Squad.

The film depicts the British military evacuation from the town of Dunkirk in 1940. It is Nolan’s first major project since Interstellar in 2014.

Dunkirk is scheduled to hit movie theaters July 21 of next year, according to Vanity Fair.