Chapter 4

Prof. Frankly tells the group that the Crystal Star is located in the Creepy Steeple, near a small town named Twilight Town. When Mario & co. get to Twilight Town, they discover that the village is under a curse cast by a monster who lives in the steeple. Using a new Black Chest Demon power, the group reaches the steeple, and battles the monster. During the battle, the monster uses an ability to steal Mario's name and body, transforming Mario into a shadowy version of himself. Mario's partners claim the Crystal Star and leave with whom they think is Mario. Meanwhile, the Shadow Sirens are in Twilight Town, planning on defeating Mario and his partners with their new weapon: the Superbombomb. However, Beldam seems to have lost it, prompting her to blame Vivian and to force her to search for it. The real Mario returns to Twilight Town, and helps Vivian with her problem. Out of gratitude, she joins Mario's party. They eventually discover that the monster's name is Doopliss; after telling Doopliss his name, he is weakened and flees to Creepy Steeple. Mario and Vivian chase him there and they fight once more. Mario and his new partner defeat Doopliss, allowing Mario to regain his name and body and to reclaim the Ruby Star.

At the X-Naut base, TEC-XX asks the Princess to participate in a sort of "quiz show" with him. By doing this, she discovers what the "treasure" of the Thousand-Year Door really is: the "treasure" is actually an ancient demon. The Princess then sends these news to Mario. Meanwhile, Bowser continues his quest for Crystal Stars by flying up to Glitzville in his Koopa Clown Car. However, it malfunctions halfway there, and he travels underwater to return to Rogueport. After he and Kammy return, he orders Kammy to continue her research on the Crystal Stars.

Back in Twilight Town, Mario and his friends receive the message from Peach. They reveal the next Crystal Star and visit Prof. Frankly for details.

The English name for the chapter, as well as its Spanish, Italian, and French translations, are referencing the Ernest Hemingway novel, For Whom the Bell Tolls.