The central tympanum illustrates the Apocalypse with a central Christ surrounded by four beasts (Revelations 4-5); the twenty-four Elders and angels are in the voussoirs. The tympanum to the left depicts Christ's Incarnation, the one to the right, his Ascension; thus the three tympana read together present a unified theme: Christ's entry into human history, his departure, and the end of time.