Ten-year-old Lilly is perfectly content to be hauled around the world by her scientist parents in pursuit of boomerang beetles and lily pad leeches. So when they decide to leave her behind with her gray-as-dust great-uncle Ernest (a librarian!) while they head for the Shipwreck Islands to study the frangipangi fruit fly, she’s crushed. One day chez Uncle Ernest, a flock of homing seagulls delivers an ominous note from her parents: “Have hit reef, sinkin.” The next thing Lilly knows, she’s on a sailboat on her way to rescue them, lost at sea with the frumpy-fierce pirate Mrs. Teagarden: “Aye, well, that’s a problem, trusting pirates. Even if ye’re a pirate yerself,” she says. Lilly, a notorious worrywart, especially about the treacherous sea, finds her fears blasted away by the ocean spray when she bravely takes the tiller of Last Chance. This transformation from skittish bookworm to swashbuckling pirate girl is the real buried treasure in this enjoyably preposterous, emotionally resonant, library-revering adventure. Shepperson’s cartoonish pencil illustrations are as wonderfully detailed, action-packed and good-humored as the story. (Adventure. 8-12)