Flush, by Carl Hiaasen (Knopf, $16.95; ages 10-up). Fans of Hiaasen's first kids' book, the 2003 Newbery Honor-winning Hoot, should be just as happy with Flush, another comic eco-thriller with an undercurrent of outrage. It's summertime, school is out in the Florida Keys, and Noah's dad is in jail for having sunk the local casino boat. Dad is convinced that the Coral Queen's sleazy owner, Dusty Muleman, has been emptying his holding tank into the marina basin -- in Hiaasen-speak, "dumping hundreds of gallons of poop into protected state waters" -- thereby jeopardizing swimmers' health and baby sea turtles' lives. As Noah's little sister succinctly says, "That is so gross." Problem is, Dad can't prove anything, especially sitting in the clink. It's up to Noah and a cast of mismatched allies to nail Dusty. As in Hoot, the far-fetched plot and nonstop one-liners belie a dead-serious exploration of the messy politics of conservation.

The Vacation, by Polly Horvath (Farrar Straus Giroux, $16; ages 10-up). If it's a Horvath tale, don't expect to see much of parents. In The Vacation, they're out of the picture by Chapter 2, off pretending to be missionaries, or Jane Goodalls, in Africa. Henry, their son and our narrator, is left home in Critz, Va., in the care of two eccentric, irresponsible aunts. (" 'What's that? What's that sound?' asked Aunt Magnolia. . . . 'Is there a neighbor loose?' 'No, that's Henry,' said Aunt Pigg, 'the little boy that Katherine had. He's twelve years old. He lives with us.' ") After a sudden health crisis, however, Aunt Magnolia decides she wants "to live." Henry is removed from school, and the unlikely trio sets off first for Virginia Beach and then, when the beach proves dull, on an open-ended road trip across America. (" 'Where are we going?' I asked. 'Anywhere we like. That's what a vacation is,' said Aunt Pigg.") It's hard to tell who's looking after whom. But when Henry's parents return, it's instantly clear that he has blossomed under his aunts' lackadaisical care. Horvath's dry humor may be a tad subtle for many young readers. But for those who get it, The Vacation could prove positively educational.

Picture Books

Pecorino's First Concert, by Alan Madison, illustrated by AnnaLaura Cantone (Atheneum, $15.95; ages 4-8). "Everyone thinks Pecorino Sasquatch is the silliest boy in the world," this winningly absurd yarn begins. Look what happens when Pecorino's doting mother takes him to a concert conducted by the world-famous Vittorio Pimplelini: The lad is on his best behavior, but when the two arrive early, Mom errs by heading to the ladies' room. "The colossal room was carrot-colored from floor to ceiling. . . . Except for the many musical instruments sleeping onstage, Pecorino was alone. But from his orange velvet seat, he could barely see the bright, brown violins and the sleek, silver flutes." What's a boy to do but sneak onstage for a closer look? It's a bit of a problem, of course, when he ends up inside the tuba, stuck fast despite his best efforts to "wiggle, wossle, and wamboodle himself out." The wordplay is matched by equally inventive and high-spirited drawings by the Italian illustrator AnnaLaura Cantone.

Shanghai Messenger, by Andrea Cheng, illustrated by Ed Young (Lee & Low, $17.95; ages 8-12). " 'Xiao Mei,' Nai Nai says, 'Uncle invites you to China this summer.' " Nai Nai is Grandma, and Xiao Mei is an 11-year-old girl, "half Chinese, half not," who is understandably anxious about traveling alone all the way from Ohio to Shanghai to meet her "big family." This beautiful book recounts the ups and downs of her trip -- strangeness, kindness, foods both familiar and exotic, old gardens and towering modern buildings, a school, a market, new words, aunties, uncles and cousins -- in blank verse so smooth it doesn't feel like verse at all. And Ed Young's delicate, lovingly detailed drawings capture every step of the journey from shyness to elation: "I want to stay in Shanghai forever," Xiao Mei concludes.

Ella Takes the Cake, by Carmela and Steven D'Amico (Scholastic, $16.99; ages 4-8). Ella, the pachyderm who won hearts last year in Ella the Elegant Elephant, is back with a problem especially familiar to small girls. She badly wants to help out in her family's bakery, but ovens and knives are dangerous, and she's not allowed to do much besides sweep -- until the delivery man forgets a special cake. Surprisingly, Ella's mom agrees to let her put it in a cart and pull it behind her bike to the lighthouse. The book's appeal lies not so much in Ella's predictable misadventures as in the detailed depiction of her sunny Mediterranean island's geography. The endpaper maps are almost as absorbing as the map of the snowplow's rescue route in that classic of yesteryear, Katy and the Big Snow.

-- Elizabeth Ward