Serena and Ann both get detention after school. When the teacher leaves to go on a date, the two girls compete to see who can finish the assignment first. Ann gets weak from lack of energy. She tricks Serena into closing her eyes and begins to steal her energy when they are interrupted by a renegade cardian who is causing a ruckus outside. Serena transforms but is too weak to attack the monster. With the Moonlight Knight's encouragment, however, she regains her strength and defeats the cardian.