"The Lost Cup? You don't want to know about that". Aidan has been thwarted at every turn, in his efforts to find out where the mysterious lost cup is hidden, or if it even really exists. A year after the escapades of Gaelic football mad twins, Aoife and Aidan Power, along with their four best friends in Twin Power: Throw In, the Droichead Beag gang are back! However, all is not rosy.

Cracks are starting to show as the gang's strong foundation creaks under the strain of new friendships with players from their rival club Gorman, along with football injuries and tense must win matches. With all this tension in the background, Aidan becomes fixated on finding the mysterious Lost Cup which was allegedly hidden 100 years ago during the Irish Civil War. Why will no one talk to him about it? Will a school trip to the GAA museum in Croke Park shed any light on this mystery? How is the lost cup linked to rivalries between Droichead Beag GAA and Gorman GAA? Can Aoife and Aidan solve this mystery, reunite their gang of friends and return to having fun on the football field?