Giles Barnes and his family have just moved into a very strange house. Creeks, rustles, and fluttering sounds fill his bedroom. His mother says there are no such things as ghosts, but Giles decides to investigate. With help from new friends Tina and Kevin Quark and their ghostometer, the team solves the mystery, and gets rid of the ghosts for good!

When Giles, Tina and Kevin see books moving in the library, all by themselves, 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' own common-sense magic to get things back to normal.

The third title in the "A bad case of..." series, this story features once more Giles and his friends Tina and Kevin Quark, who are always inventing something weird and wonderful. Tina is involved in building a robot for the school science project, but things do not go as she had planned.

Giles, Tina and Kevin are hired by the rich and eccentric Miss Frost to uncover the mystery of her deep and overgrown swimming pool—and discover not one, but two real live dinosaurs!

An old church tower has a problem with bats, but when Tina’s homemade Bat Zapper attracts more bats than it repels, the boys take matters into their own hands. Or is it really a vampire they’re up against?