Fern anxiously waits for the bookmobile’s final August visit so she can speak to Miss Parcae alone. Inside, the bookmobile is back to its ordinary, bright daytime state, but Fern notices Miss Parcae looks seriously ill and unsteady.

Fern bluntly asks what the powder spell did to Miss Wellwood and whether Fern has killed her. Miss Parcae insists that a spell must be finished or it “metastasize[s],” and explains Rose’s working simply made Miss Wellwood experience what it was like to be Rose; since Rose survived, Miss Wellwood will too.

Fern recognizes the woman on the witch book’s cover as Miss Parcae, who notes Fern is the first girl to see through her glamour. Miss Parcae admits the book has been given to other girls to see who would truly take to it, and she praises Fern for reading deeply and being “called” to the Craft. Miss Parcae speaks of a wider, dangerous future and hints at the witches’ long fight to survive coming persecutions.

During a coughing fit, Miss Parcae reveals she is dying of liver cancer and explains the coven’s “library” is a lineage of shared memories passed from witch to witch. Miss Parcae implies it is time to pass those memories on to someone new, which prompts Fern to propose Holly as a safer candidate than Fern herself.

Miss Parcae says Holly could join them only if Fern proves Holly is needed and strong enough by performing a true working; Miss Parcae suggests Holly break the heat by making it rain. That night Fern tells Zinnia, expecting relief, but Zinnia immediately calls the witches liars and accuses them of only hurting people. When Fern admits she actually gave Miss Wellwood the full dose after previously denying it, Zinnia feels betrayed and shuts Fern out, while Fern clings to her plan: Holly must run away with the witches.