Royal Nap: 9

With the ""Baaap, Bleep, Blaap"" of trumpets, the ""Whup Whup, Fupa Fup"" of flapping flags and the ""Klink, Klong, Kalink"" of swords, the castle of King Gordo is, indeed, ""a noisy place."" Such tongue-twisting sound effects are integral parts of Stevenson's pictures, which feature a cast of animated animals, among them, in the role of king, an imposing hippo that wears purple robes and a jeweled crown. But each day the castle clatter stops promptly at one o'clock, the hour of the Royal Nap. When the hiccuping of the king's pot-scrubber (a bedraggled mouse named Gerald) prevents the cranky monarch from sleeping, he banishes the poor fellow to the Cold and Snowy Land. Nevertheless, naptime doesn't improve until the increasingly red-eyed royal discovers a sleep-inducing sound: the singing and lute-playing of Phoebe, the castle's plate-scraper, who is Gerald's daughter. The savvy girl strikes a deal with the king that brings her father home-and ensures the king serene snoozing forevermore. Black makes a promising debut with this perky tale, studded with amusing asides. Well matched with Stevenson's inimitable art, the story will keep any youngster awake and eager for the next syllable. Ages 3-8. (Apr.)