The Church often punishes priests who commit some sin or grave offense. This way is to send them to a retreat, to a secluded place where no one knows them and where they can think about what they have done.
That is what we see in this film, in which there are four priests in a house far away, in the shore of the coast, a place where no one goes. In the house there is only one person, who is a caretaker who is responsible for making food, washing clothes, making the purchase, etc.
The four priests have all the time in the world to purge their guilts, repent and make amends, something they seem to be gradually achieving, but something will happen that will disrupt their evolution.
To the house comes a fifth priest who is having a bad time. What he did tormented him too much, so that he revolutionized the house, ending with the calm that reigned until now and causing the other four priests to remember why they are there.