One day a new mer-girl came to the
coral reef. This mer-girl was much bigger than Rosie and the others and it swam
much faster. This big mer-girl was called Sienna. Rosie had heard about Sienna.
Her tail was as powerful as the waves, her breath was as stinky as mouldy
seaweed and her teeth were as sharp as daggers. The other mer-people were very
scared of Sienna and stayed away from the cave in which she lived. But Rosie wasn’t
afraid. She was cross! Sienna had taken her pearl necklace and she wanted it
back! So Rosie went to visit Octavia the incredibly clever octopus.