Lucifer. Beelzebub. Satan. Old Nick. Antichrist. Mammon. Old Scratch. Evil One. The Devil. He is known by many names across the world and across the centuries. You may have your own name for him. You may imagine his form, his shape, his voice, his presence. You may have seen his portrait in artwork, in paintings, in film. You've doubtless heard stories of his power. You may have seen his shadow in dark news reports. You may tell yourself he is a cautionary tale, a childish fable; that you have nothing to fear. The central question this film sets out to interrogate is one that has been argued by the finest minds in philosophy and theology, by the illiterate, by rich, by poor, old, young, since time immemorial. The film examines this question through the life of one man, Malachi Martin; an Irish priest who dedicated his life to battling an ancient evil. Malachi Martin; exorcist. Using first-hand interviews, dramatic reconstruction, archival evidence and Martin's own words, this documentary will follow Father Martin's incredible crusade from the 1970's through to his death in 1999. So. Does the Devil exist?