For reluctant altar boy Martin Moone growing up in Boyle,Roscommon with three older sisters is no picnic. Come his twelfth birthday his sisters are not over-generous with the presents but his parents give him a Readymix bike. Sadly this is not safe from local bullies,the Jonner and Conner Bonner,and Martin has to turn to his imaginary friend,banjo-strumming Sean Murphy for - rather questionable - advice on acquiring a bully-protector.
Martin befriends new boy Trevor but there is a purpose, as Trevor's family are happy to have him round for meals whilst his own mother Debra is spending all her time canvassing for presidential candidate Mary Robinson. This involves a visit - for financial backing - to the creepy local fish magnate 'Touchy' Feeley, who certainly lives up to his name and leaves Debra wondering if she really wants his support
Due to having to wait for his sisters to use the bathroom Martin finds himself over-sleeping and Sinead takes advantage of this to put eye shadow and make-up on him,so that when he innocently arrives at school it is assumed he is gay. To save time in getting to school Martin,encouraged by Sean,takes inspiration from world events and the fall of the Berlin wall by dismantling his garden wall to create a short cut. Debra,meanwhile,sets out to be a Weight Wishers leader and teach weight reduction,though nobody comes to her classes.
As Martin experiences a sexual awakening after watching female tennis players and cartoon princesses on television Uncle Danny,his father Liam's brother, an ultra-cool musician,comes to visit. Danny is a man of the world and Martin turns to him for information on the birds and the bees,much to the annoyance of Liam - and Sean,who,seeing himself as redundant,hangs out with 'Crunchie' Haystacks,another boy's imaginary friend.
Following an awkward confirmation,in large borrowed shoes,during which he is renamed Martin Martin, Martin decides that he would like to be an altar boy after all and,helped by Sean,determines to be the best in Boyle. However before long he tumbles to the fact that these sweet little lads are actually an organized crime ring who delight in intimidating Father Linehan. At the same time Fidelma takes a shine to Dessie Dolan,the chief choir boy, and decides that she has also discovered religion. Debra and Liam wonder what went wrong that drove two of their brood to ...
Martin has a week to go before he finishes at primary school and Sean believes that he should leave in anarchic style so that he will never be forgotten - but anarchy does not come naturally to the hesitant Martin. Debra and Sean regret promising Sinead she could go on the girl guide jamboree if she did well at school and set about trying to scupper her school work though the biggest shock comes when Fidelma and Dessie announce their future plans.