Set in the near future. As a consequence of an ecumenical movement (Vatican Council IV), the Catholic Church has joined other religions and has eliminated much of the original dogma of Catholicism. A group of Irish monks rebel against this situation and react back to the past: they begin to say Mass in Latin and act according to traditional Catholic dogma. So, Rome decides to send a representative to investigate what is happening
Unfortunately the movie The Catholics is not yet available on HBO Max.