This is a book about biological pollution - the plants and animals that have spread around the globe on the back of human movement, those that have traversed the boundaries of natural habitats and have begun to erode their new adopted environment.
The author documents the grave consequences of humankind's intended and unintended introduction of alien species into South Africa. While some rivers have lost their natural fish populations, the west coast is choked over with mussels from a far-off country; the Cape Floral Kingdom's rare plants have come under increasing threat; sensitive renosterveld has been reduced to a few isolated islands of resistance; dams and lakes have been taken over by an umbrella of aquatic plants; and water is being consumed voraciously by thirsty alien trees.
The book is, however, not a story of despair. Instead, it encourages scientists, citizens and policy-makers to continue with their efforts to contain and eradicate invasive alien species.