The Secret Mermaid. Penguin Peril

Continuing her quest to rescue the sea creatures who have been spirited away by dark magic, secret mermaid Molly helps her friend, Animal-Keeper mermaid Phoebe, to track down the lost penguins. A clue from some friendly seals leads the mermaids into icy water, where it seems the penguins are trapped at the top of a huge iceberg.