Containment chamber

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En Sentac walks towards Swarm's containment chamber. (TV: The Halloween Apocalypse)

A containment chamber was a device.

The Timonic Fusion Device was kept in a briefcase in a containment chamber on the Third Moon of Kikrit. (AUDIO: Weapon of Choice)

Containment chambers couldbe used to keep a conscious, powerful being imprisoned for extended periods of time. It consisted of a large stake-like structure to which the prisoner was shackled, standing, as well as a square base which projected an invisible, cubic forcefield around the stake.

The Division imprisoned Swarm in a containment chamber which remained functional for millennia, being checked in on every thousand years by Division agents. Eventually, however, it broke down; Swarm took his opportunity when the power shorted out to kill En Sentac, fuelling a regeneration. In his new, stronger form, he effortlessly broke out of his shackles and escaped. (TV: The Halloween Apocalypse)