Taking their anti-social edge one step further, seventeen-year-old Gem and her friends Mira and Lo have decided to go Underground. Their activities will be "extreme", "anti-establishment", "avant-garde" and "debauched".

While Gem makes an underground film and Mira sets about pursuing "boys-without-barcodes" no one knows what it is that Lo – the most subversive of the three – has planned. But in the back of her mind, Gem's worried. She feels the balance of the trio's friendship is always weighted against her. And as the weeks draw closer to Christmas, appearances start to deceive and relationships flounder. For all the promise of the group, Underground seems a dark place to be.

It will take great films, bad poetry and a pantheon of inspirational guides – from Andy Warhol to Germaine Greer – to help Gem work out the true meaning of friendship, where family fits in, and that the best parts of life aren't always underground.