Chapter 0, titled The Nightmare Knight's Return, starts on page 78 and ends on page 137.
Sir Carrot says he escaped from Caketown Castle when Cordelia and Peridot arrived and petrified most of the castle's inhabitants. He also has a heart pendant from Princess Parfait, who remains trapped in the castle.
Cucumber, Almond, and Carrot enter Saturday's tower on the Flatbread Flatlands and find only her butler, Brambleby. Saturday, herself, has apparently gone fishing in the Ripple Kingdom and taken the Dream Sword with her. The trio goes upstairs, where they find a massive treasure pile stolen from Caketown Castle. Almond takes a new sword, and the last Disaster Stone is found. Peridot enters to fight for it, but Almond humiliates her and hands it over, as she looks forward to having an epic quest with the Nightmare Knight as its villain. Cucumber and Carrot are upset at this. Cucumber reluctantly takes a wand from Saturday's pile, and they leave.
In Caketown Castle, Cordelia threatens the BLT Trio for their incompetence and Tomato's flirting with Parfait. After they exit, Peridot brings her the last Disaster Stone, which they use to summon the Nightmare Knight.
In the port town of Saltine, Cucumber, Almond, and Carrot find that there are no boats to the Ripple Kingdom, due to attacks on the way by "a giant squid". A young inventor, Cosmo, introduces themself and offers a ride aboard the S.S. Cosmo, but neglects to mention that he intends to use them as guinea pigs for a test run, and sends them speeding across the sea, where they are shipwrecked by the "giant squid", Splashmaster.