Lewis Barnavelt has had enough of adventure. He’s battled evil sorcerer returned from the grave, ancient Hawaiian ghosts, and even stopped the world from ending a time or two. Now he’s ready for a nice, long, relaxing summer vacation without any magic at all. But somehow, trouble seems to still be following him. Are all the accidents he keeps having bad luck? Or are they somehow related to the hooded figure he keeps spotting around town and the mysterious Curse of Three? It’s up to Lewis to find out, and fast. The clock is ticking and someone’s time is numbered...

The Sign of the Sinister Sorcerer (2008), by Brad Strickland, is the twelfth book in the Lewis Barnavelt series.

"This is children's mystery in the most classic sense. Strickland has captured Bellairs' brooding gloom, which pervades these stories, even in a place as generally sunny as Michigan." - Janie Franz.

Then, in something like a silent explosion, bright purple light erupted from the circle, so intense that Lewis squinched up his eyes. Mrs. Zimmermann vanished entirely in the glare. A moment later it had faded, leaving blobby dark patches wavering and dancing in Lewis’s vision, and gasping, Mrs. Zimmermann staggered out of the circle and made her way to the armchair, where she collapsed. "My stars! I haven’t done the evocation spell in nearly thirty years. I’d forgotten how much it takes out of a body. Lewis, be a dear and bring me a glass of water, please. And bring back a damp cloth to get rid of these circles. We don’t need them any longer."

Lewis got on his hands and knees and rubbed out the chalk marks. “What did you do?” he asked, standing up again.

Mrs. Zimmermann finished her glass of water. “Something that should not be done often or lightly. I consulted the spirits regarding this house.... I have a strange feeling here this morning, and I wanted to make sure I was correct.”

"I felt it too," said Lewis impulsively. "It’s like no one has lived here for years."

Mrs. Zimmermann looked at him, her eyes thoughtful as she adjusted her spectacles. “It’s even worse than that, I’m afraid. Lewis, you are going to have to be brave.... The puzzling truth is, Lewis, that all of your uncle’s magic is absolutely vanished from this house. Nothing remains! It’s gone like a candle flame blown out by the wind, leaving not a rack behind....”

...Lewis tore to the back stair of the south wing. Here and there in the house were stained-glass windows, and that one was the easiest to see from inside. It was the most vividly colorful of them all, and it always changed scenes from day to day. But today it was just an ordinary leaded oval of clear pebbled glass showing no picture at all.