The Sea Of adventure: the adventure Series (Book 4)

Philip, Dinah, Lucy-Ann, Jack, and Kiki head to the remote Scottish isles for what should be a peaceful convalescence. But the sea hides more than just waves. There are rumours of war criminals, secret codes, and mysterious sightings on isolated cliffs. When Jack spots strange lights flashing from the sea caves at night, the children begin to suspect their quiet retreat is a hub for something sinister. A trail of coded messages, a vanished scientist, and an island that doesn't appear on any map pull them deep into danger. And when their only boat disappears and Kiki refuses to go near the tide line, they realize they aren't alone on the island. But who is watching them from the cliffs and what are they waiting for?