Tyler and Lucinda set out to spend another summer at the mysterious, wonderful, and eerie Tinkerfarm. The dangerous challenges they will face here are unimaginable and surpass everything they have experienced so far. A dark secret looms over the Tinkerfarm. Tyler and his sister Lucinda feel this immediately as they return to the small secluded valley deep in the countryside. The farm, with its unique animals, dragons, unicorns, and water serpents, is under threat. Not only do the ever-present security measures reveal this: fences, surveillance cameras, and even dangerous new creatures are in play. When Uncle Gideon also disappears without a trace, Tyler and Lucinda are left to protect the farm and all its animals on their own. But what does the shady housekeeper Miss Needle have in mind?.