Matthew Crawley, eat your heart out.

Gone are the days of Downton Abbey. For Dan Stevens, who played the mild-mannered heir of Downton for three seasons of the Emmy-winning series, all eyes are on the future, and his finger is on the trigger, as the leading man of The Guest, a new action thriller directed by Adam Wingard and written by Simon Barrett, the team behind You’re Next.

In The Guest, Stevens stars as David Collins, a mysterious man who visits the family of his fallen comrade, a fellow Afghanistan war veteran named Caleb. As he becomes closer to Caleb’s family, things take a turn for the deadly, and it becomes questionable whether or not David really is who he says he is. Questions about his identity aside, one thing is clear: David (and Dan Stevens) is a real badass with a gun in his hand.

Check out the trailer below, courtesy of Yahoo:

The Guest arrives on Sept. 5.