Gunpowder follows Catesby and his fellow conspirators as well as Robert Cecil (Gatiss), the king's spymaster-in-chief, whose network of informants pursued the plotters in a game of cat and mouse. The period piece is written by Ronan Bennett ( Public Enemies ) and directed by J. Blakeson ( The 5th Wave ). It was developed by Bennett, Harington and Daniel West.

The 5th November - The Gunpowder Plot!Whilst Guy Fawkes played a pivotal role, the man who dreamed up the plot and was its driving force was Robert Catesby (Harington), a 30-year old Warwickshire gentleman.

Catesby is a committed Catholic at a time when Protestant England persecutes Catholics relentlessly. The authorities directed by King James spymaster in Chief Robert Cecil (Gatiss), hunt down, torture and execute priests while lay Catholics are subject to oppression and the loss of their property. They must practice their religion in secret, risking imprisonment, fines, harassment and even death.

Catesby is unable to stand by while his fellow Catholics suffer, and despite the peaceful protestations of head Jesuit Father Garnet (Mullan), doing nothing is not an option for a man like Catesby. He starts to recruit friends and relatives, swearing them to secrecy as he devises an audacious plan. His astute and capable cousin Anne Vaux (Tyler) becomes suspicious about his activities and fears the consequences will be the exact opposite of what Catesby intends.