In the final episode of Stranger Things, the kids from Hawkins have their final confrontation with Vecna, not in the Upside Down, but in the previously little-seen alternate dimension known as “The Abyss” (aka, Dimension X). The visual difference between the two is striking. While the Upside Down is blue-tinted with red lightning and, seemingly, always enveloped in shadow, the Abyss is a dry, hazy, craggy, rocky yellow desert, at the center of which is a dead-looking tree. Having only glimpsed it briefly in previous episodes, the Abyss seemed wholly new to fans.

