Gunpowder, which was developed by Harington, script writer Ronan Bennett and Daniel West, depicts the story of the conspiracy to blow up the British House of Lords in 1605 in an attempt to assassinate King James I, Variety reported.
The event is celebrated on Nov. 5 in Britain as Guy Fawkes Day, the name of one of the conspirators.
The clip, released Monday, features the Game of Thrones star as Robert Catesby, who was the mastermind behind the plan, and Cullen as Guy Fawkes.
"My wife is dead. My name disgraced. My friends and family tortured and hanged. We must strike at the root. Fawkes will light the fuse and I Robert Catesby will blow the king and all his men to hell," Harington says in the teaser.
The cast also includes Peter Mullan, Edward Holcroft, Shaun Dooley, Robert Emms, Derek Riddell and Mark Gatiss.
Directed by J. Blakeson, the three-part Gunpowder is set to premiere on the BBC this fall.