Some frescoes, made by brothers Pietro and Ambrogio Lorenzetti around the 1330s, adorn the transept. The fragments are part of a cycle of frescoes devised for the chapter house and the friary cloister, and were detached from their place of origin and moved to the Basilica in 1857. The third chapel to the left of the altar houses a Crucifixion by Pietro, framed by a nineteenth-century motif. The scene focuses on the upper part of the representation, converging on Christ and only portraying the onlookers half-length. The painting, made after their stay at the site of the Basilica of Saint Francis in Assisi, shows the same spatiality of the body and sense of expressiveness that characterize the Sienese artist’s later works. The pain is expressed by the swirling of the desperate angels, by Mary, who faints backwards and is supported by other women, by the hunched shoulders of young John, who manifests his despair in a grimace of pain. It is one of the highest and most dramatic works made by the Master, in which the accuracy with which the body of Christ is shaped recalls some of the sculptures made in Siena in that time by Giovanni Pisano. On the other side of the transept, in the Bandini Piccolomini Chapel, are the paintings of Pietro’s brother Ambrogio, which depict St. Louis of Toulouse, who bids farewell to Boniface VIII, and the episode of the Martyrdom of the Franciscan . . .