There are two surviving versions of Calderón's play on the Faust theme, El mágico prodigiosos. The first, preserved in an incomplete autograph manuscript, was written for performance in the town of Yepes on the Feast of Corpus Christi in 1637, with staging appropriate for the traditional Corpus mystery play, the auto sacramental. The second, first published in 1663, is an adaptation for performance in the playhouses of Madrid. The circumstances of the play's textual identity are unique in the seventeenth-century Spanish theater and the purpose of this complete edition is to reveal in action not only the dramatist's developing vision but the imperatives of a remarkable commercial theater and its symbiotic relationship with the religious order of the day. At the same time, the opportunity has been taken to provide a study of the play and its two versions, its sources and its context; a lengthy introduction, extensive notes, and a full textual apparatus accompany the composite text.