On Aio, a tidally locked world of eternal day and night, a human transport ship warps and crashes with no hope of rescue. With food dwindling, trainee botanist Cassie scours alien flora for sustenance while the crew braves the wilds to salvage tech and jettisoned cargo. But their presence unknowingly poisons a delicate ecosystem of veilgrass and glowing ash-blooms—triggering catastrophe.