One year after the death of his beloved musician father, thirteen-year-old Benny Oh begins to hear voices. The voices belong to the things in his house - a sneaker, a broken Christmas ornament, a piece of wilted lettuce. Although Benny doesn't understand what these things are saying, he can sense their emotional tone; some are pleasant, a gentle hum or coo, but others are snide, angry and full of pain.
When his mother develops a hoarding problem, the voices grow more clamorous. At first Benny tries to ignore them, but soon the voices follow him outside the house, onto the street and at school, driving him at last to seek refuge in the silence of a large public library, where objects are well-behaved and know to speak in whispers. There, he falls in love with a mesmerising street artist with a smug pet ferret, who uses the library as her performance space.
He meets a homeless philosopher-poet, who encourages him to ask important questions and find his own voice amongst the many. And he meets his very own Book - a talking thing - who narrates Benny's life and teaches him to listen to the things that truly matter.