Rubeus tells the Negamoon Sisters that Serena's greatest fear is thunder, and devises a plan to use this against her and Rini. Prizma sends a droid named Thunderclap to create a long thunderstorm to force Serena and Rini to appear. Serena is caught in the downpour and runs home. Luna reminds her to pick up Rini. However, after a while, Rini thinks Serena is not coming, and runs off. Shortly afterward Serena arrives, and when she does not find Rini, she goes looking for her.
Amy, Raye, Lita, and Mina are forced into a cafe (separately) by the storm. Serena runs into Darien, and he agrees to help her search for Rini (for Rini rather than Serena, whom he is still trying to avoid). After talking to a mysterious woman through the Luna Sphere, Rini tries to return to the future, but her time key does not work, striking the cafe and causing it to go zero gravity. As Rini begins to cry, the crescent moon appears on her forehead, and Prizma and Thunderclap are alerted to her presence.
Thunderclap goes to the cafe and attacks Rini, where Serena transforms into Sailor Moon, but gets zapped by Thunderclap until Tuxedo Mask arrives and throws a rose through her drum, breaking it. Sailor Moon destroys Thunderclap with Moon Scepter Elimination, blasting her out the window as she dissolves into dust. The storm disappears, and Rini returns the gravity to normal.
- This is the second time where Rubeus and the Negamoon Sisters are looking for Sailor Moon and/or Rini, rather than taking over crystal points. The first was actually the first episode in their arc.
- First and last appearance of Droid Thunderclap.