With Dessie, Fidelma and baby Rose back living with the Moones, the choir master sets to work on a fortune-making business idea to help him give his family their own home. And what does he think Boyle needs most of all? A Catholic bookshop, of course. As Dessie aims to put Catholicism on the map, he learns of a strong need for literature on more than just his own faith and, soon, his shop houses a "cacophony of catechisms", although nothing Protestant.

Liam is less than convinced by Dessie's 'cash cow' and sets to work on plan B - having an extension built in the garden. With a wealth of building materials now at his disposal, Martin also sets to work on a construction project, as he renovates his new 'penthouse'.