The maniacal Jervis Tetch, aka Mad Hatter, has never really gotten his time in the spotlight in Batman adaptations — often only a sideline player in Batman's largest stories, the Mad Hatter has ...

When Batman learned that Jervis’ tech was used to control Jim Gordon, he put Nygma’s riddle together. Riddler puts Mad Hatter's device into Gordon’s glasses frames to frame him (get it?).