Polly is a great mechanic. She’s been fixing her little sister’s bike, but is getting fed up of how annoying Peigi is, and how her beloved dad is never around to see all the great stuff she does. So when the local gang arrive with a bike to fix, and ask her to join them, she jumps at the chance. Finally some recognition! But what starts off well enough - finding junk in the river, cleaning it up and selling it – soon turns much darker when Polly betrays her sister to save herself and impress the gang. As gang leader Donnie Dan shows his true horrible colours, will Polly do the right thing, ditch the gang, and make amends with Peigi?