Board Thread:The Panopticon/@comment-24361711-20151122175815/@comment-1783865-20151122191935

Yeah, perhaps. Or perhaps the Doctor doesn't know that "They" might be the Quantum Shade, just like when the Gelth managed to cheat him into believing they were few and just searching refugee.

No. The lines doesn't speak out that the gas possesses, but if you watch the episode, the gas seeks out the Raven and possesses it, after which the Raven seeks out the chronolock. The gas is the Quantum Shade. The Raven was just a tool (or body) used by the Quantum Shade.

Whether They and the Quantum Shade are the same or not, can we agree that the Quantum Shade is the gas, not the Raven? The Raven is possessed by the gas as shown in the episode.

Perhaps the Doctor thinks that it is just the one Quantum Shade, Perhaps "They" are a council with Quantum Shades of some kind.

Yes, I know that that is my theory, I haven't said it wasn't. That is just as much my theory only, as the other one is his theory.