Sapphire and her brother conor can't forget their adventures in ingo, the mysterious world beneath the sea. They long to see their mer friends once more. But a crisis is brewing far below The Ocean's surface, where saldo...Sapphire and her brother conor can't forget their adventures in ingo, the mysterious world beneath the sea. They long to see their mer friends once more. But a crisis is brewing far below The Ocean's surface, where saldowr, the wisest of the mer, guards The Tide Knot.