The world has become a dangerous place. Despite the environmentalists' best efforts, the atmosphere has turned toxic, destroying almost all life—plants, animals and most of humanity, too. Survivors live in domes protected by chitin shields, serving one or other of the two great companies, Lord Vane's Tempestas or Lord Sine's Genrich, with their very different visions for mankind's future. A long period of uneasy collaboration between them is about to end. Far from these centres of power stands the Museum Dome, where persons unknown have assembled mankind's finest paintings and artefacts and installed a young man, Fogg, as its curator. Here he has laboured for three years without a single visitor and with only AIPT, his automated physical trainer, for company. Then a single mysterious pill—a momenticon—appears in the museum and triggers a series of bewildering events, embroiling Fogg and his unexpected new companions in a desperate fight against the dark forces which threaten to overwhelm all that remains. And time is running out.