JUNE 1 It was a five-mile walk out Dungeness Spit to the lighthouse. There wasn’t much of a view, a chilly fog limited Cassidy’s sightlines to a few hundred feet, but there was plenty to see. Thousands of birds joined her for her walk along the nature sanctuary: gulls fishing close ashore, cormorants standing out on logs with their wings spread to dry, and grebes diving deep whenever she drew too close. Even a couple of seals followed her, looking like dogs paddling happily through the waves until the moment they dove in a sinuous roll. Her favorite were the sandpipers racing up and down the beach following the leading edge of the lazy waves, occasionally pecking at the sand. She couldn’t see what they caught, but they intently followed each wave down the long beach, then raced madly bac