Story : Dolphins and whales have evolved to have the largest brains on the planet. In terms of body size, they are second only to humans. Today, however, researchers are discovering that dolphins are not only intelligent, but also sensitive. In tonight's amazing BBC documentary, two stories of survivors of terrifying encounters with sharks suggest that dolphins may be able to recognize human emotions, understand when we are scared, when we feel pain. The rescues, which took place in the Red Sea and in New Zealand, are proof of the intelligence of dolphins and also of their willingness to help another species. In this episode, many interesting reports: Parker is a Canadian child suffering from a severe congenital immunodeficiency. To avoid the risk of getting sick, Parker cannot leave the house, play with other children or go to school, and is forced to live a prisoner in an aseptic environment, often even in hospital. This is why children like Parker are called "bubble children".