Help! We Have Strange Powers! (Goosebumps Horrorland #10) by R.L. Stine

Keep a Cool Head!

Jillian and Jackson freak out when they suddenly can read people's thoughts. But the trick turns to terror when the twins are stalked by a strange scientist who wants to know exactly what's on their minds. Will the twins ever lead normal lives again?

Shady Lady?

Not in HorrorLand they won't. There are free meals, free games, and free falls down the Doom Slide. Someone's watching their every step. But is she friend or foe?