The Sampo knows this. That's why it reached out to the human twins Alex and Ben O'Leary, brothers who could pave the way forward and bridge the gap between the human race and the merrow. Now both boys have heard the call of the sea, drawing them to the tides from which they originate. They've lived with the tug - the urge that begs them to return to the depths - for all their lives. A desire they did not know how to name. With the help of their merrow friend Lia, the brothers are united in their quest to find out who they are, why they're here, and most importantly what they need to do next. Nothing is forever... even blood.