THE NIGHT THE MOON CAME BY

Emilia doesn't believe in trolls or ``ghosts and ghastly creatures with no heads,'' but one night when the moon comes stalking on its long legs and shines through the window, her little cousin is certain he hears ``Nightlings'' in the attic. It's ``just the cat hunting for mice,'' scoffs Emilia, but when he describes the dreadful creatures (realized in delightfully eerie detail in èhlin's watercolors, where fey grotesques peer from every corner), she creeps up to the attic with him to see. Here a real owl and old toys seem as weird as the fanciful spooks; and when the grownups come to see what's going on, they also find a real tramp, who apologizes and is given a snack. The conclusion is ambivalent: the tramp converses amiably with the Nightlings, while the cat plays with them ``even though they didn't exist.'' This offbeat Swedish book may scare timid souls, but those with stouter hearts will find the chills delicious. (Picture book. 5-8)