Two years after their first magical encounter, Emily Volnik and her younger brother Jessup return to Scotland to visit the ancient Castle Keep. To their absolute delight, the Boggart is still there! This mischievous, shape shifting spirit has lived in the castle for centuries, and he is busy playing hilarious tricks on the castle's new owner, Mr. Maconochie. At Jessup's urging, Mr. Mac takes the kids on a camping trip to Loch Ness, where a high tech expedition is searching for the legendary Loch Ness Monster. Naturally, the invisible Boggart tags along for the ride. On their very first night, the Boggart is thrilled to discover that Nessie is actually his long lost cousin! But Nessie has forgotten how to change shape and is stuck in his prehistoric monster form. Now, the Boggart and the kids must team up to help save Nessie from the snooping scientists. Filled with suspense, humor, and unforgettable magic, this brilliant adventure is a joy to read.