A thick fog has found its way up north to the lighthouse family, surrounding the cliffs and waters below. Always ready to lend a hand, the lighthouse siblings Whistler and Lila help Seabold the dog to guide small ships to land. When they find a turtle who needs help, they have found a friend. Creating some especially expressive critters, Preston McDaniels's drawings appear throughout this fourth book in the series for readers 6 to 10, and Cynthia Rylant's text dramatizes the wonders of eaching out to others.