The position of the play by Lope de Vega is involved with that of Oliver. Don Juan de Castro flees to England because of the unlawful love of his stepmother, the Princess of Galicia. His ship is wrecked on the English coast, and the captain, Tibaldo, is cast ashore in a dying condition. To free the latter's mind from unrest, Don Juan pays his debts of two thousand ducats, though this is half of the hero's possessions. He hears that the princess Clarinda is promised to anyone of princely blood who wins an approaching tournament. While he is sorrowful that he cannot enter the contest, because of his poverty, the ghost of Tibaldo appears to him one night and promises the necessary equipment on condition of receiving one-half the gains. The next morning he finds everything ready and wins the princess. He is later taken prisoner by one of the contestants through a ruse, and is carried off to Ireland. By the ghost's advice, his stepbrother and double comes to London and takes his place, while Don Juan is freed by force of arms and restored to his wife. After some years, when the couple have two children, the stepbrother falls ill of a dreadful malady, which can only be cured, Don Juan learns in a dream, by the blood of his children. So he slays them and gives their blood to the sick man to drink. They are found alive by a miracle; but Don Juan is troubled, and does not find rest till the ghost appears and tells him that the only remedy for his affliction is to fulfil his promise of a division. The hero prepares to divide his wife, when the ghost stops him and explains that the demand was only a test. As Schaeffer pointed out, [131] Lope's plot is clearly taken from Oliver, probably from the Spanish translation issued in 1499. Indeed, the drama follows the romance with far more fidelity than could have been expected of such an adaptation. The various elements of the motive appear without essential alteration. The play El mejor amigo el muerto, listed for convenience as Calderon, has suffered, in contrast to Lope's play, from many changes. Prince Robert of Ireland and Don Juan de Castro are wrecked on the English coast. The former finds the sea-captain Lidoro in a dying condition, and refuses to give him aid. Don Juan, on the other hand, finds Lidoro's body, which a creditor keeps from interment, and pays for his burial out of his scanty savings from the wreck. He then goes to London, where there is trouble because Queen Clarinda will not marry Prince Robert. Don Juan is cast into prison on a false charge, his identity being unknown to the queen, though he is recognized by Robert. He is saved by the aid of Lidoro's ghost, nevertheless, lays siege for Clarinda's hand, overcomes Robert, and so becomes king of England.