Danny Wallace is about to turn thirty. Recently married and living in a smart new area of town, he's swapped pints down the pub for lattes and brunch. For the first time in his life, he's feeling... well ... grown-up.

But something's missing. Something he can't quite put his finger on. Until he finds an old address book, containing just twelve names. The names of his best mates as a kid. Where are they now? Who are they now? And how are they coping with being grown-up?

And so begins an epic journey – from Berlin to Tokyo, Los Angeles to Loughborough. He meets a Fijian chief. A German rapper. Some ninjas. But how will they react to a long-lost friend turning up out of the blue to see if they're coming out to play?