Once, no man on Earth thought that life on Mercury was possible since the planet is locked with one side perpetually facing the Sun. Scorching heat on one side and eternal darkness on the other seemed to guarantee that Mercury must be uninhabitable. But when the inhabitants of Earth first started to voyage through the Ether, some daring explorers also turned towards Mercury-and discovered how wrong the previous assumptions about the planet had been.

Because even if the one side of Mercury is dominated by vast hot deserts with lakes filled with molten metals and the other side is a seemingly lifeless waste with its giant glaciers of ice and ammonia, there is still a small strip of land between these two extremes that thrives with life. This zone where the cold and hot sides meet always stays in the same twilight and at the same temperature-this is the realm of the mighty World River, which spans the whole planet and is a lifeline for the primeval fauna and flora on both river

• A supplement for the Space 1889 role-playing game.
• Expands the game's setting to include the planet Mercury.
• Provides new locations, characters, and adventures in a steampunk-inspired Victorian era.