Having survived an influx of giant, poisonous Siberian snow spiders (Seven Spiders Spinning, 1994), the rival boys and girls of Miss Earth's class in Hamlet, Vermont, face another set of prehistoric critters: a herd of ghost mammoths hunting through the centuries for a misplaced youngling. In the wake of a classroom argument about the existence of ghosts, the Tattletales (girls) gleefully don fright masks and beehive wigs ("" 'There is nothing quite so terrifying as hairstyles that have gone out of fashion' "") and send the Copycats (boys) fleeing down spooky Hardscrabble Hill in panic, where there are actual ghosts--indistinct mounds that appear at the first sign of peanuts and wander about with a mournful air. With the help of the new boy, Salim Bannerjee, a newly deceased pet mouse named Jeremiah Bullfrog, plus lots of chocolate donuts from the local bakery-cum-auto repair shop, the Copycats divine the source of the mammoths' unhappiness; they ease it with a handy baby elephant ghost that has followed Salim all the way from the Bombay Zoo. Then, using many cans of hair spray, they give the obliging pachyderms new hairstyles to turn the tables on the Tattletales. Maguire's wit sometimes slips its leash, but the climax is sidesplitting and the gender rivalry thoroughly skewered, although the heartwarming ectoplasmic adoption scene prompts a Thanksgiving Day truce between the factions.