As their stay on the Galapagos draws to a close, Monty and his family find out what's being done to protect the islands and their wildlife from the threat of invasive animals.

In 1978, the Galapagos Islands were designated a Unesco World Heritage site, signifying their unprecedented importance to the world. Forty years on, biologist, broadcaster and conservationist Monty Halls returns to his `favourite place on Earth" to investigate the wonders and challenges that both define and threaten this jewel of nature. Monty is accompanied by a unique research team - his wife Tam and daughters Isla and Molly, who for three months will experience this utterly unique way of life.

Marine biologist Monty Halls and his family are settling into life on the island of Isabela in the Galapagos, where they discover it's not without its challenges. The family find flamingos in an unexpected place and get to know a big fish with a bad reputation. Daughter Isla becomes a young field assistant helping to tag baby Hammerheads, while Tam and Monty mark their wedding anniversary underwater with over 20 endangered sharks.

Two years on since Monty Halls, his wife Tam and daughters Isla and Molly first travelled to the Galapagos islands - one of the most unique and ecologically important places on the planet - the family head back to discover why it faces a fight for survival. In the opening episode, Monty experiences the mighty volcanic power that created the islands, mum Tam makes a solo voyage in search of threatened giant manta rays, and Molly, the youngest, has her first snorkelling experience.