When Sophie the baby sea otter learns about the horizon she is determined to swim all the way there. Her Mum warns her it’s impossible but Sophie thinks it doesn’t look that far, so she sneaks off on an epic journey.

On her travels she finds a magnificent lighthouse, befriends a walrus, meets a whale and dives deep under the water to swim with colourful tropical fish – but no matter how far she travels that pesky horizon eludes her.

As night falls Sophie realises that perhaps her Mum was right. Tired and alone, she bristles with fear when she spots a mighty ship heading in her direction. She has swum so far, how will she ever make it home?