A university student is forced, by his lack of funds, to take the only lodging he can afford. In a strange part of the city he had never seen before, on a street named "Rue d'Auseil," he finds an apartment in an almost empty building. One of the few other tenants is an old German man named Erich Zann. The old man is mute and plays the viol[a] with a local theater orchestra. He lives on the top floor and when alone at night, plays strange melodies never heard before. Over time, the student gains Zann's trust, and eventually learns of his secret, that the old man has discovered melodies and rhythms of sound of an almost otherworldly nature. Zann plays these sounds to keep back unknown and unseen creatures from Zann's window, which is said to look out into a black abyss, most likely another dimension.