Crucible

The Crucible is a.....something from the IDW portion of the Generation 1 continuity family.

The Crucible, whatever it was, was at the centre of the Simanzi Massacre.

Fiction

IDW comics continuity

During the Massacre, it took the involvement of Optimus Prime to prevent over a thousand Autobots (such as Pyro) and neutrals from falling into the Crucible. Pyro's Profile