The fresco cycle of the Old Sacristy

The pivot and origin of the cycle are located at the center of the groin vault where the Christ Pantocrator towers. Christ is depicted in a mandorla, surrounded by angels, in the act of blessing. On Christ's knees lies an open book bearing a phrase from the Gospel of John «Ego sum lux mundi qui sequitur me non ambulat in tenebris sed habebit lumen vite» (I am the light of the world; whoever follows me does not walk in darkness but will have the light of life), an obvious reference to Saint Bernardino, a figure of importance in fifteenth-century Siena. In the lateral panels are the four evangelists, of whom only Saint Matthew and Saint John remain, and in the upper and lower panels the doctors of the Church are depicted in pairs: Saint Ambrose and Saint Jerome, Saint Augustine and Pope Saint Gregory, the latter pair shown seated on a cloud. Around these panels we finally find, in a deteriorated state, the ten prophets. As for the iconographic program of the cycle's walls, which was far more complex and erudite, it provided for the depiction of the Apostles' Creed, divided into ten sections corresponding to the bays of the walls, following a scheme in which each bay is divided into an upper lunette and a lower rectangle. In the upper lunette the articles of faith are represented together with an apostle and a prophet with a cartouche that serves to explain the depiction; in the lower rectangle, on the other hand, episodes from the Old and New Testaments related to the article of the Creed above are depicted. The richest depiction is perhaps that of the Last Judgment, in the seventh bay, on the wall adjacent to the corridor. In this fresco Il Vecchietta achieves an extraordinary result, especially in the expressiveness of the figures and the emotional tension of the scene. In the upper lunette, at the center, the figure of Christ is surrounded by angels, prophets, saints, the Madonna and Saint John. The angels at the feet of the Madonna and Saint John hold two books on which are recorded the precepts of Santa Maria della Scala and the list of the seven deadly sins, addressed to the damned. At Christ's feet is Saint Michael who separates the blessed, guided by angels, from the damned driven to hell by demons. Below this scene is the tragic episode of Daniel's Vision of the Chariot of Fire, in which Christ hurls a trail of flames toward the damned, who despair, creating a clear separation from the host of the blessed placed on the left, who, unlike the damned, appear calm and elegant.