A little boy asks at bedtime, "Why does the day have to end?" His mother responds, "So night can begin." "Nothing ends," he finally concludes, as a "thin new moon" shines high. Glowing artwork in warm colors created in oil paint on wooden panels brings a new dimension to one of Zolotow's hallmark lyrical picture book dialogues between a parent and child. The reassuring counterpoint of a loving adult's certainty about daily and seasonal cycles is comfortably juxtaposed with her open-ended, honest responses to abstract queries natural to all children. (Ages 3-7)