When Mostyn, an aging Pembrokeshire farmer on the brink of bankruptcy, runs into young Jethro, his fortunes appear to take a positive turn. The pair secretly mobilise the locals of the village pub to help put on the greatest money-spinning event in the history of Little Emlyn: Lewistock. But things do not go to plan. Moneylenders, drug dealers, the county council and the bank all set a collision course with Mostyn and Jethro. As the clock ticks down to the August Bank Holiday event and the young revellers begin to pour in from all corners of the county, the tension heats up. It's not clear who exactly will get out alive.