Every day, Karl Kohlhoff, an elderly bookseller, delivers books to customers at their homes. These are special customers, for whom Karl selects special books. Karl names each of his clients after a character from a book (Hercules, Faust, Effie, and Mr. Darcy) and visits each regularly, taking a book walk along the same route.

But one day, a girl joins him, disrupting the ritual and literally bursting into the lives of Karl and his customers.

This is an extraordinary story about friendship and understanding, about books, bookwalkers, and the paths life takes us.