A rare book dealer finds himself at the heart of a string of paranormal events when he is hired to find the last two copies of a text, The Nine Gates of the Kingdom of Shadows, capable of summoning the Devil.
A briefcase with undisclosed contents – sought by Irish terrorists and the Russian mob – makes its way into criminals' hands. An Irish liaison assembles a squad of mercenaries, or 'ronin', and gives them the thorny task of recovering the case.
