The Adamantine Mummy Case was a sarcophagus-like device that kept a single adult prisoner immobilized, with the head exposed for recognition purposes. Cocooned, the prisoner had great restriction of movement, being barely able to move the fingers a few inches.
The device absorbed sunlight and turned it into unbearable heat, so as to keep the prisoner uncomfortable and torture him or her. Purportedly, the material was strong enough to paralyze superhumans.[2]
History
When Johann Shmidt and the Exiles took over Castle Doom, taking advantage of Victor von Doom's vacation in the French Riviera, they turned Doom's weapons against him and knocked him down using Chemi-Sleep Gas,[2] then immobilized him in the Adamantine Mummy Case.[2]
Intending to humiliate him before his former subjects, they put him on display in a Latverian public square.[2][1] The Red Skull did not remove Doctor Doom's Armor, either because he could not or wanted ease of recognition.[2] Unfortunately, Doom's armor had a hidden thermo-energizer device in the cuisse, which he barely managed to activate manually; that technology harnessed the heat energy directed against him, instead powering the armor until it was strong enough to break the case in small pieces.[2][1]