The trailer was released on Saturday and shows several steamy scenes. Spoiler alert!
The video teases what appears to be a scandalous hookup involving a naked or near-naked Jimmy Kent (played by Ed Speleers), who seems to have been caught in the act, as well as a romantic kiss by Tom Branson (played by Allen Leech) with a mystery woman.
Meanwhile, it appears Lady Mary Crawley (played by Michelle Dockery) may be getting some action of her own.
The clip also shows show newcomer Richard E. Grant. The actor, seen on Girls' most recent third season as Jasper), plays Simon Bricker, a guest of the Grantham family at Downton Abbey.
And in one of the most shocking scenes, a man is shown carrying a woman while escaped from a massive fire. Is Downton Abbey burning down?
The show returns for season 5 on the United Kingtom's ITV network on Sept. 21 and in the United States on PBS on Jan. 5. 2015.