History
Doctor Doom developed this prison specifically to hold the Human Torch, his fire-generating enemy.[1][2] It included a tank made of glass and steel, with a steel reservoir and a canister that pumped in[2] a specific inert fluid developed by Doom himself.[1] The fluid was prevented the Torch,[1][2] or any other fire-using superhuman,[2] from generating plasma,[1] flames or any other external combustion,[2] but provided oxygen enough for the prisoner to breathe.[1][2] The glass walls were relatively weak and could be broken by a hardy human, however. An external control panel with buttons could be used to fill in the tank, empty it or open it.[2]
Doctor Doom had one of these devices in the basement of the Latverian Embassy of New York City, and attached its control panel to the ones of three other unique cages for the other members of the Fantastic Four - the Force Cage, the Molecular Cage and the Plasteel Sphere. Once, Doom imprisoned the Human Torch in this item and his colleagues of the Fantastic Four in the others. Doom intended to make them witness his triumph by restoring his original body and summoning the Beyonder. Mister Fantastic talked his way out of this situation, being released himself while Doom was teleported away. Having this chance, Fantastic released the Torch and his other partners.[1]Notes
The book Machines of Doom #1 fails to include a section on the "Availability" of this device.