The twelfth and final book in the famous Lewis Barnavelt series. It is finally the summer holidays, and Lewis is looking forward to the break from school and spending time with his best friend Rose Rita, his Uncle Jonathan, and his neighbor Mrs. Zimmermann. But Lewis's hopes for a peaceful summer holiday are shattered as one accident after another plagues him. Is all his bad luck really just a coincidence? Or does it have something to do with the mysterious hooded figure he keeps seeing?