'Gunpowder' Preview: The Cast, The Plot, And When It Premieres On HBO

Get ready for an explosive three nights on HBO as Gunpowder has its U.S. premiere. Game of Thrones actor Kit Harington stars in the three-part BBC miniseries, which has its HBO debut on Monday, December 18.

To help you prepare, here are some fast facts about the cast of Gunpowder, including the plot and everything else you need to know about the series before its HBO premiere.

What is Gunpowder about?

That is an excellent question. Here is the official plot synopsis from HBO.

"The story focuses on Catesby, a committed Catholic at a time when Protestant England persecuted Catholics relentlessly, as his refusal to abandon his religion brings him to the edge of financial, social and psychological ruin. Mark Gatiss (Game of Thrones, Sherlock) plays Robert Cecil, King James' spymaster, who directs efforts to hunt down, torture and kill priests, while rank-and-file Catholics are subject to oppression and the loss of their property."

"The miniseries chronicles the evolution of the plot, the selection of collaborators to carry it out, the gathering of resources and the obstacles to its execution — as Catesby's team plays a deadly cat and mouse game with Cecil's ruthless spy network."

When does Gunpowder premiere?

The miniseries premieres December 18 on HBO.

Kit Harington as Robert Catesby and Liv Tyler as Anne Vaux in 'Gunpowder'

What time does it air?

Each episode of the series airs at 10 p.m. EST and as you may have guessed based on the time it is set to air, Gunpowder is an intense and violent series.

What other shows would I have to like to know Gunpowder would appeal to me?

If you like costume dramas such as Showtime's The Borgias, Game of Thrones, or The CW's Reign, you will probably be interested in Gunpowder. For context, Reign chronicles the early life of Mary, Queen of Scots, whose son James VI and I, would become King James I. The "gunpowder plot" took place during King James I's reign.

What can I expect tonally?

Expect a lot of plotting and displays of graphic violence. When the series originally premiered on the BBC back in October, The Guardian reported that viewers had been "shocked by the violent scenes" that comprised the series.

Who is playing the lead character on Gunpowder?

Kit Harington stars as Robert Catesby, the mastermind of the plot. As mentioned on HBO's Medium page, Harington "is a descendant of Robert Catesby, the central figure in the story…."

Who are the other cast members starring in the series?

Kit Harington is not the only familiar face you will see if you tune into Gunpowder. In fact, the series has quite a few.

Actress Liv Tyler, who starred in the Lord of the Rings films and HBO's The Leftovers, stars as Catesby's cousin in Gunpowder. Ozark star Peter Mullan plays a Jesuit priest named Father Garnet.

Liv Tyler, Edward Holcroft, and Kit Harington in a scene from the HBO broadcast of 'Gundpowder'

Edward Holcroft, who plays the inquisitive Dr. Jordan on Netflix's Alias Grace, stars as Catesby's friend and fellow conspirator, Thomas Wintour. Rounding out the cast is Tom Cullen, who is currently starring as the lead in History Channel's Knightfall. In Gunpowder, Cullen stars as the infamous Guy Fawkes.

How many episodes are there and how long are they?

There are three total episodes and each one is an hour-long.

Is Gunpowder a series, or a miniseries?

It is a miniseries.

Quick reminder, where and when can I watch Gunpowder?

You can watch the Kit Harington series when it premieres December 18 at 10 p.m. EST on HBO. Gunpowder concludes December 20.