In Helen Dunmore’s Ingo (link to Amazon), two siblings discover the secret that took their father away.
When Sapphire and Conor’s father disappeared, supposedly drowned in a storm, they know for a fact that he’s still alive. Nobody believes them, even their mother, but they make a pact to find him and bring him home.
Then they start to feel the pull of the sea, the same pull that took their father. Instinctively following it, Sapphy and Conor discover Ingo, another world beneath the waves. With the blood of both humans and the Mer in their blood, they can travel willingly to Ingo and back home again.
But while Ingo is full of wonder, and Sapphy feels that she belongs there, it is also dangerous. Because every time she travels to Ingo, she belongs a little bit more to it and less to her home on land. And if she belongs to much to either Water or Air, she will have to give up one of the worlds she loves…
Ingo is surprisingly painless for a book written in present tense, and Sapphy is a perfect narrator with both her quest to find her father and her question of which world to belong to. Throughout the book I felt clearly Sapphy’s longing to go to Ingo and her frustration at being held back, and when I was finished I wanted to go to Ingo, too.