After Mrs. Seabird lays just one egg instead of her usual two, she and Mr. Seabird take in a pretty foundling egg that hatches into what looks like a turtle. They name him Sandy and raise him like his nestmate, Bertie. Still, nature declares itself: each day, Sandy explores the sea while Bertie soars in the air above; but at night both return to their parents and the home nest. The lesson here is a bit obvious, but Carrier's smoothly crafted illustrations--dominated by repeated forms that echo the sea's ripples and the maternal egg, with all rendered in the soft colors of the Easter season--are sure to appeal.