A Strange Case of Magic

Also known as A Bad Case of Magic.

When Giles, Tina and Kevin see books moving in the library all by themslves, they know they have to investigate. But Tina's amazing ghostometer doesn't pick up any ghosts, so what could that mysterious presence be? Nobody expects what they actually find – and once again, it takes a dose of Giles's own common-sense magic to get things back to normal.