A quantum stasis field was a type of energy field capable of preventing a Changeling from altering their form and fixing them into their solid state. A prototype of this device was first constructed by the Obsidian Order by 2371. During the joint Obsidian Order-Tal Shiar strike force into the Gamma Quadrant, Enabran Tain gave Elim Garak the task of interrogating the Changeling Odo and learn any secrets about the Dominion or about his people. Without the ability to revert to his natural form, Odo experienced intense agony until Garak finally deactivated the device allowing him to return to his dormant state. (DS9 episode: "The Die is Cast")