For the plot of his play, Fletcher depended upon Miguel de Cervantes, one of his regular sources; The Chances borrows from La Señora Cornelia, one of the Novelas ejemplares, first published in Spain in 1613 and translated into French in 1615.
Current scholarship assigns the play to 1617 (it refers to Jonson's The Devil is an Ass, performed the previous year), as a work staged by the King's Men at the Blackfriars Theatre.
[2] During the years of the English Civil War and the Interregnum when the London theatres were officially closed to full-length plays (1642–60), material from The Chances was extracted to form a droll titled The Landlady, which was later printed by Francis Kirkman in his collection The Wits (1672).
As the city's other houses are being shut up for the night, John sees one that remains open and well-lit; curious, he looks in, and is confronted by a woman who thrusts a mysterious bundle into his arms.
A strange woman accosts him, mistaking him for the man she hopes to meet; when she discovers her error, she appeals to his sense of honour to protect her and guide her to safety.
Offended by the unfair odds, John draws his sword, fights on the Duke's side, and drives off the attackers, wounding Petrucchio's kinsman Antonio.
John and Frederick are caught up in the affair – but they manage to ascertain that the Duke and Costantia are pre-contracted to marry, which palliates Petrucchio's offended honour.
The muddle is eventually straightened out, when the four men track down this Costantia and learn that she is another woman of the same name – she is Antonio's courtezan, who has robbed him of gold and jewels, expecting him to die of his wounds.