With Lent approaching, Ted receives a phone call from his rival, Father Dick Byrne, who says that he and his fellow priests on Rugged Island will be giving up their vices.
The next day, Sister Assumpta wakes the priests at 5 a.m. with an air horn at an extremely close range of the Fathers (it is evident that she quietly sneaked into the Fathers' room while they were still asleep) and puts them through a grueling ordeal, which includes spending a while outside in bathtubs of ice-cold water, being dragged behind a tractor, having objects thrown at them, and being nearly fired at by her when they try to sneak carefully toward a table she is eating at.
To escape from this rather cruel Sister, whose philosophy stems from Matty Hislop, Ted and Dougal reluctantly go to Rugged Island's parochial house that night to see about staying with Dick Byrne.
Ted and Dougal return to Craggy Island, only to find that Assumpta had discovered a basket of chocolate eggs while they were away - her addiction of chocolate, upon her seeing the eggs while she is calling her associates, takes effect overnight, much to the surprise of Ted, when he makes the discovery on the morning he and Dougal return.
Mrs Doyle subsequently returns from her Lenten pilgrimage, and upon entering the living room, she finds Ted, Dougal, and Jack overindulging in their vices more than ever.