If we are lucky in our lives, our friendships will be rich and varied. They will be shared with those with two legs, with four legs, with whiskers or clean faces; they will come dressed in the simplicity of childhood or the professional attire of adult life; some will span decades, and some will be only fleeting. But the thing they will all have in common is that life is not only unimaginable - but unimagined - without them. In these gorgeous personal reflections, Andrew O'Hagan explores friendship through music and poetry, memory and history, illuminating the many ways and reasons that people come together, and how our lives are all the better because we do.