In the summer of 1911 school friends Jack, Seth, Wally and Alfie form the Cork Club – a secret friendship group which will see them through lazy summer days, first encounters with the girls in the village and their ongoing feuds with Tommy Adams and his gang. When war breaks out in 1914, it is not long before they are all serving in the trenches, where their friendship is tested more than any of them could have ever imagined. The repercussions of their actions are felt for decades to come.