When the Scottish owner of Castle Keep died the ancient castle went to his Canadian great-nephew Robert Volnik. There was no way the Volniks could keep the castle so it was sold to an Edinburgh lawyer Mr. Maconochie. Two years later Emily Volnik and her younger brohter Jessup return to the castle for a visit. To their delight the Boggart a mischievous shape-shifting spirit who has lived in the castle for centures playing tricks on the owners is still there making Mr. Mac coubt his won sanity as strange things happen. At Jessup's urging Mr. Mac takes them and Tommy Cameron a local friend on a comping trip to Loch Ness Where a new expedition with advanced underwater equipment is planning another search for the Loch Ness Monster. The boggart comes along and on thier first night there he is entranced to rediscover Nessie a boggart cousin who has long forgotten how to change shape and remains in the prehistoric-monster form he long ago adopted. Beautifully imagined and beautifully written this is an unforgettable adventure filled with humor suspense and wonderful characters. It is a stunning companion to Susan Cooper's earlier book The Boggart.