Kira was a young dolphin who had always dreamed of joining the great whale migration. Every year, the whales travelled thousands of kilometres across the open ocean, and every year, Kira watched them from a distance. However, this year was different, because a competition had been announced: the fastest and smartest young dolphin would win the honour of leading the pod. Kira's heart raced with excitement, but also with fear, since she had never swum so far before.
The first challenge was to hold her breath for a long time. Like all marine mammals, dolphins breathe air through a blowhole on top of their heads, so they must come to the surface regularly. Kira practised diving deep and holding her breath, but she was not the strongest. Therefore, she decided to use her brain instead of her muscles. She remembered that dolphins can use echolocation to find their way in the dark water, and she began to practise sending out clicks and listening to the echoes.