Toby is grocery shopping. How sane and normal. To be sure, she's doing it with a towering troll, and her own Fetch, whose presence is inexplicably long -- her showing up is supposed to mean that Toby dies, and so does May, the Fetch -- and May is noticing the pixies in the produce department, but that's sane and normal for Toby.
Then a messenger shows up demanding that she attend the queen, and the question is whether they can put the perishables away in the frig beforehand.
Well, all the queen wants to do is make her Countess of Goldengreen, but after that's a ball, held by her liege lord, which she must attend, and there, she sees her old enemy Oleander -- half the start of all the troubles, back in the opening of Rosemary and Rue -- and Luna falls mysteriously ill. And then Toby is summoned to Lily's side, to find that she's poisoned and dying as well.
And on the story wends. On its way, it hits the beauty of cherry blossoms, a daring rescue where a selkie takes off his seal skin entirely, Tybalt's revealing that he knows a secret about Toby that he won't tell her because she'll think he's lying, the secret coming clear and Toby's concluding that Tybalt was right, Oleander's appearing to Toby except that she positively can not be there, a chemistry professor who's a Tylweth Teg, and a kangaroo court.