Professor Richard Fortey travels to the rainforests of Madagascar - an ancient island that has spawned some of the most extraordinary groups of plants and animals anywhere in the world. From beautiful Indri lemurs, toxic frogs, and the cat-like giant mongoose called the fossa, to evolutionary oddities like the giraffe-necked weevil and the otherworldly aye-aye, he uncovers the secrets of the evolutionary niche - examining how, given millions of years, animals and plants can adapt to fill almost any opportunity they find.