According to the text in this complex, near-ethereal exploration of a teen girl’s inner awakenings, 17-year-old closed-mouthed Clio has quite a history behind her, including world travel, a bestselling video game named Dive! and a strange tattoo. When her mother ships her off to her scheming, goofball, Homer Simpson–like father on a boat off the coast of Italy with an eclectically offbeat cast of cards, Clio soon finds herself plunged into a world full of mystery, both in terms of the boat’s destination and whether or not the affections of the very good-looking shipmate Aidan are aimed at her or her chatty Swedish roommate. Johnson’s latest, filled with intricately drawn images of the sea, historical conceit, mythology and a touch of fantasy is meanderingly literary, full of unforgettable moments and much more complicated than readers may grasp as they turn the pages. Clio’s own rocky, inner curiosities complement the calming, ocean landscape where jellyfish, sunken ships and treasure lurk below the surface of cool, blue waters set against the Italian coast. An iceberg of a romance in the vein of Sarah Dessen. (Fiction. YA)