- Vindice comes in disguise to Lussurioso, who says he needs a messenger to help him as he tries to seduce a virgin who lives nearby.
- Awkwardly, the virgin turns out to be Vindice's sister, Castiza. Of course, Lussurioso doesn't know he's talking to Vindice, so he doesn't realize the irony… but the audience does. Lussurioso does know that Hippolito is Castiza's brother, though, and he's proud of having tricked Hippolito into unknowingly helping Lussurioso seduce his sister (1.3.150-160). Not a nice guy, this Lussurioso.
- As if to prove the not-a-nice-guy theory even more, Lussurioso says that if the girl can't be seduced, maybe they can bribe her mother to pressure her into sleeping with Lussurioso (1.3.167-169).
- Lussurioso asks Vindice to swear to work hard for him. Vindice does it halfheartedly, but it's clear that he's troubled by the way he has been unexpectedly and accidentally maneuvered into a situation where he's expected to betray his sister (1.3.180-186).
- Lussurioso exits and Vindice laments the situation he's wound up in. As he wrestles with his conscience, he comes to the strange conclusion that this will be an opportunity to test the goodness of his mother and sister. Sounds a bit strange to us, but it seems to make him happier—he's quite confident that they will prove virtuous.