A beloved sculpture is stolen by an acid-spitting rock creature in Barcelona. A smart, brave thirteen year-old girl deals with her father's ditzy girlfriends in Seattle. A doleful sandstone gome battles wolf hounds and guard geese at Cragganbogle Castle on the Western Isles of Scotland. When Finnley and Hadley's Seventh Grade class is invited to spend a vacation in Spain these unlikely events are drawn together into an adventure filled with more danger, weird food, snooty popular girls, underground cave cities and evil bog witches than they could have hoped for.

Can they survive the Rock Pit of Torture and Justice, attacks by a cloud of midges and dive-bombing bonxies, and the embarrassment of Hadley's mother's naked Druid dance under the Midsummer moonlight? Only if their scruffy, rude, bad-tempered companion, Wullie, can do the impossible.