Elizabeth Levy

"The principal of Jill and Gwen's school promised to spend the morning on the roof if the kids read one thousand books during their reading marathon--and they did! Now he's on the roof, and he's going to read an original science fiction story Gwen wrote..."

Gwen and Jill's discovery of some mutilated library books strangely links up with a dog show in which they have entered their dog.

Gwen, an amateur sleuth, sets out to discover who took her best friend's lucky baseball bat.

It's Gwen and Jill to the rescue when someone tries to sabotage Fletcher the basset hound's mission in space.

When Rebecca, a seventh-grader, is paired up with her friend Scott for a dance class at school, she learns a lot about who her real friends are.

Brian and his younger sister Penny become involved in a mystery at the science museum where they are working on a woolly mammoth display for a science fair.

Chip, an invisible boy, and his friends investigate the mysterious disappearance of yogurt-covered raisins, mixed nuts, and ginger snaps from their classroom.