January 1916, Europe is deadlocked in a titanic struggle. Seven members of a secret society The Irish Republican Brotherhood meet in a church hall on the outskirts of Dublin to plan a rebellion, the consequences of which are felt on two continents, igniting a flame which would result in independence six years later.

Daniel Barton, the enigmatic head of Dublin's notorious G Division, seems powerless to prevent unfolding events, which ultimately leads to the destruction of his native city. To uncover the conspiracy, he reactivates an old informant The Apiarist, one of the seven conspirators.

Sean Maguire returns to his native city to avoid conscription and consequently gets drawn into Dublin's criminal underworld working for Edy Barrett, The Princess a kingpin who runs brothels in the city's notorious Red Light District Monto. He rekindles with his childhood sweetheart Amy who works for The Princess with disastrous consequences for both.