Theseus jumped, dropping his wand. Professor Eularia Vance, the Deputy Headmistress and expert in Transfiguration theory, stepped into the candlelight. She looked at the grey sludge with an expression of mild distaste.
Vance waved her hand, and a chalkboard scraped itself across the floor to face them. She tapped it. Four words appeared in chalk: gamp 4 guide