Suspendium was an artificial compound developed by Doctor Sivana. He used it to trap the Marvel Family in a force field bubble which kept them in a state of suspended animation for over twenty years. Unfortunately for Sivana, he unwittingly trapped himself and his own family within the same stasis bubble.
People who were stranded on Suspendium
- Marvel Family (including Lieutenant Marvels and supporting cast).
- Sivana Family (including Beautia and Magnificus)
- WHIZ Radio staff (including Sterling Morris and Cissie Sommerly)
- Shazam's Squadron of Justice
- Ebenezer Batson: His pact with Satan was near the deadline when he was released.
Other Earth-S people's relationship with the 20-year Suspendium period
- Shazam the Wizard and Kid Eternity, as spirits, have no known activities at this time.
- Captain Nazi voluntarily put himself in suspended animation due have no worthy opponent.
- Ibac's alter ego was reformed and working as street cleaner.
- Herkimer was reformed and working in a traveling circus. 
- The inactivity of Mister Mind can not be understood since he had forged his death in the 1940s.
- Black Adam was dead in this time; he would be resurrected by Dr. Sivana some time after.
- King Kull's whereabouts are unknown in that time.
- Mister Atom: His body was inert and stranded in 2053. After the 20-year Suspendium period he was pulled from the future and reactivated by King Kull. 
- The Suspendium was an argument to explain why the Marvel Family and the rest of the cast have not aged since the time that the Fawcett comics stopped being published.
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