Audrey Wood, , illus. by Bruce Wood. . Scholastic/Blue Sky, $15.95 (40pp) ISBN 978-0-439-44337-1

In this follow-up to Alphabet Adventure, mother and son Woods again unleash young Charley's set of three-dimensional, lower-case letters on what is best described as a why-dunit. When the alphabet takes nightly roll call, something isn't right. Little x is missing, and the other 25 letters set off to track him down. They find him at the spooky castle of the ominously green Giant M (for Master) and discover that their comrade has become a captive but willing court musician ("tap-dancing a lullaby on a xylophone"). "I ran away because Charley never uses me," Little x whines. But when Little i (whose missing dot was the subject of the previous volume) explains Charley's plans for Little x in his mother's birthday surprise, the errant letter agrees to escape—a plan that turns out to be unnecessary, since the hulking M is really a big softie. Once again, Bruce Wood's super-saturated, digital pictures bubble with a playfully surreal sense of scale, volume and detailing, as he first shows the alphabet quaking in the shadow of M, then the Giant M blubbering—"I have a mother too"—as teardrops splash on the letters' surface. Whether the abecadarian cast is sailing to and from the castle on their pencil rocket, or picking out a present for Charley's mother from Giant M's treasure room (Little f picks a fan, Little n picks a necklace, etc.), every spread is letter-perfect. Ages 3-up. (Sept.)