One evening the Collins find their maid Mrs. Murdock at the end of their steps: dead, neck broken. Obviously she had an accident. Consequently they need a new babysitter for an upcoming big party. The sensible Helen meets little Susan Collins at the discount market and likes her, so she offers to do the job. She doesn't know Susan's teenage brother Mark - technically skilled and good in school, but restive and cunning. As soon as the parents have left, he starts psychologically terrorizing Helen and his sister with electronic tricks.
Lois Smith
Helen Giles
Christian Slater
Mark Collins
Dina Merrill
Nell Kempler
Tandy Cronyn
Evelyn Collins
Dan Ziskie
Phillip Collins
Brooke Tracy
Susan Collins
John Cunningham
Jim Kempler
Edward Marshall
Karl Yaeger
