Crucifixion of Christ between the two thieves in the central compartment, set before a vaulted space with four traceried windows. Numerous figures fill the fore- and middle-ground including the Virgin fainting at the foot of the cross with St John the Evangelist and Mary Magdalene and six figures on horseback, including Longinus and Stephaton. In the vault above the Cross, almost obscured by the foliate border of the frame, is the half-length figure of God the Father.