The Pyramid Is a Terrible-Monster's Nest! is the twenty-fifth episode of Ultraman Ace.
Seiji and Yuko go to investigate an elementary school where several children have collapsed due to strange red smoke. While there, they witness a giant pyramid rise from the ground in a cloud and help save a number of kids, including a mysterious woman named Michiru.
- Ultraman Ace Volume 7 features episodes 25-28.