Alex Gibney, one of documentary film-making's most prolific talents, has told scores of tales across his long and varied career. Few, if any, are as full of the sorrow and pity on display in Mea Maxima Culpa - a retelling of broken deaf men crying out for God's healing ways and receiving nothing but sterile silence in return. This is the story of souls filled with courage to shout, and those stained by the cowardice of reticence.

   A damning and almighty "J'Accuse", Gibney's film introduces us to Terry, Gary, Pat and Arthur - four former student's of St John's School of the Deaf. During their most vulnerable years, the boys were systematically abused by the school's head Father Lawrence Murphy. They were not the first, nor would they be the last, of his victims.

   As adults, the deaf students became militarised and took it upon themselves to make certain that the public knew exactly what Murphy had done behind closed doors. Disturbingly his crimes, both in nature and extent, were well known within the Catholic Church ; a certain Cardinal Ratzinger (later taking the name Pope Benedict) was assigned to deal with all cases of paedophile priests across the religion. The Church, as always, took to institutionalised silence on such issues - their policy of "Omerta", and dealing with all issues internally, seemingly cribbed wholesale from the Mafia.

   Gibney's film is a helacious, systematic assault on the Catholic Church, showcasing the acts of pure evil perpetrated by the institution for the sake of public relations. Generations of children can be abused by men of God but the wellbeing of victims is of much lower priority to the Church than the men who commit such evil and the reputation of the institution too. It is a sickening state of affairs.

   Yet, for a film featuring such perverse and grotesque actions, Mea Maxima Culpa also boasts images of radiant beauty. As Terry, Gary, Pat and Arthur tell their harrowing stories, their faces and hands captivate us - Gibney's movie has illuminated his subjects so as to capture the profound brilliance and honesty of sign language as their features state more words than their mouths ever could. This is the story of supreme evil clashing with voices which do not tremble, voices which will not be hushed.