Having learnt what makes crocs so deadly, Steve now wants to see if legendary monster crocs can still thrive in the protected Ndumo Game Reserve in South Africa. It's known for its high concentration of crocs. However, he's heard the protected sanctuary is under threat from people living around it, so if he can find any monster crocs, this will prove they are still able to thrive here.First he comes face to face with a living legend, the world's oldest crocodile, Henry, who is more than 120 years old. Living in captivity has allowed Henry to grow to an incredible 5 meters as he has everything he needs - he's a true monster croc. But can Steve find any crocodiles this size out in the wild?On arrival at Nyamithi pan, one of the largest lakes in the reserve, the water level is drastically low and the crocs are disappearing. Steve joins a team of scientists tagging and tracking one of the remaining crocodiles to find out where they are going.He also visits Jozini Dam outside the reserve, a man-made croc paradise, where he gets a close look at a healthy female monster crocodile, but on returning to the reserve he discovers the water from the lake has almost gone. Why has this happened and where are the crocodiles going? Steve makes it his mission to find out.Scientist Peter Calverly and safari guide Bongani Mkhize have a theory that it's the introduction of the red clawed Australian crayfish that has eroded the banks of the lake allowing the water to drain out.Following the recently tagged crocs signal Steve and the team track them to the very northern reaches of the reserve. Here Steve finally sees the monster croc he has been looking for.