It all starts out so innocently, with the two friends groaning over their mandatory appearance in the school talent show. Though they diligently research their act at the splendid National Museum of Magic, their magical mishaps cause a strange and unsettling change in Rose Rita. She grows increasingly remote and cold, spellbound in a sway of forces she is powerless to resist. With Rose Rita ever more ensnared in a web of sorcery, vengeance, and spooky creatures from beyond the grave, Lewis, his uncle Jonathan, and their friendly witch neighbor Mrs. Zimmermann must band together to save their friend from a deadly doom! But will their actions be enough to save her from the specter's fiendish grip? Or will they all share her horrifying fate?

The Specter from the Magician's Museum (1998), by Brad Strickland, is the seventh book in the Lewis Barnavelt series.

"If Rose Rita's slow, inexorable ensnarement doesn't put readers on the edges of their seats, the climactic underground encounter certainly will." - Booklist

"No," said a strange, breathy voice, a woman's voice. "Running away is no good, not with your powers. Use your strength. Teach these unworthy ones a lesson."

Rose Rita could not see anyone who might have spoken. Twirling slowly in the air, Rose Rita asked, "Who is that?"

"A friend." Now Rose Rita could tell that the voice was in her mind, and not coming from outside. "Drop down, down, and take one of them. Take Sue. That will show them!"

Rose Rita grinned. Yes, that would show them! She'd snatch Sue right off the ground and scare the daylights out of her. Rose Rita began to drop lower, lower, slowly, and then she stretched out her long, shiny, hairy arms --

Eight of them!

Rose Rita looked down at herself and screamed in terror. She wasn't flying -- she was dangling from a spiderweb. Her body had become a huge bloated thing, hairy and blue-black and round as a ball. She opened her mouth to scream, and she found she could make only a hissing noise. Thick green venom drolled out of her mouth.

She had become a giant spider!