Hide and Seek — William M. Carney

HIDE IN DARKNESS

Joey and Megan Brennan looked like two normal kids. But they each had phenomenally high I.Q.s that put them way ahead of other kids at school. It never occurred to them to wonder why they were the way they were. Until the day they were kidnapped on the way to school and taken to a hideout in South America by a brilliant scientist known as El Doctor. A man who claimed he was Joey's real father.

HIDE IN TERROR

It was terrifying being kidnapped. And even more terrifying to think that this monster could be his father. Joey had seen the projects El Doctor was working on - genetic experiments of nightmare proportions. And it didn't take a genius to figure out that he and Megan had been captured for a purpose - a shocking, evil purpose that could change him and his little sister into helpless machines!