"Frontiers are not convention but laws. Here, my lands; there, your shore—"

Solange warns Claire about the importance of boundaries between them after they accidentally touch in Part One. The caution stretches beyond physical boundaries, however. Solange knows that in their fantastical role-plays, they are always in danger of losing their identities. The sisters change in "whirligigs," to use Jean-Paul Sartre's term, and the personality of each follows the other in a never-ending circle. Each sister hates being reminded of herself through her sibling mirror-image, but they inevitably meld personalities—Solange shows Claire-as-Madame the mirrored reflection of herself and Claire and says the maids have "merged" in their hatred of Madame. Even in the role-play, then, in which their personalities do sharply diverge, the maids smash the frontiers between themselves. The boundaries are demolished in Solange's final monologue, in which she plays and addresses a number of characters.