It is the third of Huysmans' books to feature the character Durtal, a thinly disguised portrait of the author. He had already featured the character of Durtal in Là-bas and En route, which recounted his conversion to Catholicism. La Cathédrale continues the story. After his retreat at a Trappist monastery, Durtal moves to the city of Chartres, renowned for its cathedral. Huysmans describes the building in great detail.
—Summary by Wikipedia
