On the night before James is due to become a Catholic priest, his fellow trainees persuade him to come out for one last taste of freedom. Arriving drunk at a fancy dress party, he meets the beautiful Dervla. Dressed as a nun, she assumes James's priest outfit is only a costume. One thing leads to another and the two share a night of passion. Fast forward to today and Father James returns from spending nine years in remotest Africa, where he was sent the day after the party. Now put in charge of the children's First Holy Communion, he is stunned to see among the mothers, Dervla, and her sweet, charming 8 year old daughter, Aisha. With a ferocious bishop, a dangerous gangster and a host of hilarious characters in the mix, James realises Dervla means much more to him than a one night stand. Now he must decide what kind of "father" he is really meant to be.