Magnus Fin and the Selkie Secret

On his eleventh birthday, schoolboy Magnus Fin found out that he is half selkie, part human, part seal. Although he looks like a boy and lives on land, he can breathe underwater. When a rusty metal chest is flung ashore in a storm, Magnus Fin decides to investigate. But he injures his hand on the strange box, and his sealskin starts to show through. His teacher realises that there's something very unusual about Magnus Fin -- and rumours start to spread. Deep in the ocean, the great sea god ...