When their fridge breaks down Mairead and Conor set off for a farm at Skibereen to get a new - second-hand - one, taking Jock, rather against Mairead's wishes. After a bizarre way of changing a tyre and an encounter with an electric fence they reach their destination and obtain the fridge - along with a new passenger. Back home Mairead expresses her dislike of Jock but something happens to change her mind.
With Jock living with the McSweeneys more cash is needed so the boys join Mairead working at the fishmongers. The wages are low so they decide to steal and sell on a giant tuna. Not only do they bungle it but Sergeant Healy finds out. Fortunately he is dating Mairead so keeps quiet for her sake and persuades the boys to show how much she means to them.
The boys take Linda and the pregnant Siobhan to the cinema by bus but Jock has just stolen from a shop wearing a Billy Murphy mask and a vengeful, knife-wielding Billy hi-jacks the bus with Mairead and Tony Healy in pursuit. Soon the chase is on national news though Siobhan has her own news for Jock whilst Linda and Conor share their first kiss. Ultimately the passengers enjoy their experience so much that when the Garda stops the bus they decide to help Billy.