Fifteen million years ago a volcano eruption created a new island in the Atlantic Ocean above the Equator line. Little by little, a complex ecological system developed on it, the Tropical Rainforest. How did the plants arrive on the island? And how does this ecosystem work? A journey to São Tomé in search of the present, which retraces the botanical exploration of the island undertaken by the naturalist Frederico Moller in 1885.