In another likable mystery for readers making the transition from easy readers, Nate and his dog go on an urgent middle-of- the-night quest for a missing pillowcase that his friend Rosamond's cat is especially attached to. Pondering clues, Nate stumbles in deerstalker, pj's, and rapidly deteriorating slippers from his house to Rosamond's to another friend's to an all-night diner—all affectionately recorded in Simont's sure, broad strokes and colors only slightly muted by the unseemly hour. It's all satisfyingly resolved when Nate remembers something that the reader also probably missed at first. A welcome addition to a reliable series. (Young reader. 6-9)