As Steven helps Sadie cope with quitting her job at the Big Donut and losing Lars, Steven and the Gems must work together to deactivate an old Diamond Authority artifact called the Harmony Core before it destroys Earth.
- ISBN13 9781787733503
- Publish Date 29 November 2019
- Publish Status Out of Print
- Out of Print 14 April 2022
- Publish Country GB
- Publisher Titan Books Ltd
- Imprint Titan Comics
- Format Paperback
- Pages 112
- Language English