Update: Two very different trailers, one for the U.K. and one for the U.S., have been released, and I’ve included both below.

One of the films I’m most excited to see this fall is The Imitation Game, a dramatic thriller starring Benedict Cumberbatch as Alan Turing, a British cryptographer who helped crack Nazi codes during World War II but was later prosecuted for homosexuality, then a crime. The subject matter is obviously fascinating, and Cumberbatch is a highly talented actor, so all signs indicate that The Imitation Game may arrive as one of the year’s best films. Now, a teaser trailer has been revealed by Studiocanal, giving us our first real look at the tense historical thriller.

As the trailer shows, Turing’s main challenge is deciphering the German Enigma code, considered by many to be unbreakable. To this end, he enlists the help of...