H.H., a German choirmaster, is invited on an expedition with the League, a secret society whose members include Paul Klee, Mozart, and Albertus Magnus. The participants traverse both space and time. The pilgrims' ultimate destination is the East, the "Home of the Light", where they expect to find spiritual renewal. Yet the harmony that ruled at the outset of the trip soon degenerates into open conflict... It is only long after the trip, while poring over records in the League archives, that H.H. discovers his own role in the dissolution of the group, and the ominous significance of the journey itself.