Twisted is a 1986 horror

Horror film

Horror films seek to elicit a negative emotional reaction from viewers by playing on the audience's most primal fears. They often feature scenes that startle the viewer through the means of macabre and the supernatural, thus frequently overlapping with the fantasy and science fiction genres...

 and psychological thriller

Psychological thriller

Psychological thriller is a specific sub-genre of the broad ranged thriller with heavy focus on characters. However, it often incorporates elements from the mystery and drama genre, along with the typical traits of the thriller genre...

 starring Christian Slater

Christian Slater

Christian Michael Leonard Slater is an American actor. He made his film debut with a small role in The Postman Always Rings Twice before playing a leading role in the 1985 film The Legend of Billie Jean...

, Lois Smith

Lois Smith

Lois Smith is an American actress whose career in theater, film, and television has spanned five decades.Smith was born Lois Arlene Humbert in Topeka, Kansas, the daughter of Carrie Davis and William Oren Humbert, who was a telephone company employee...

, and Tandy Cronyn.

Plot

One evening the Collins family discovers their maid, Mrs. Murdock, dead at the end of their steps; her neck is broken. Evidently, she had an accident; now they need a new babysitter for an upcoming party. The sensible Helen meets little Susan Collins at the discount market and likes her, so she offers to do the job. She does not know Susan's teenage brother Mark: technically skilled and good in school, but restive and cunning; Mark also listens regularly to German marching music from the Third Reich. As soon as the parents have left, he psychologically terrorizes Helen and his sister with electronic tricks. Williams, a school jock whom Mark burned earlier in science class, is out for revenge; Mark murders him with a fencing sword. Ultimately, Mark himself is killed when Helen knocks him onto a spiked German helmet. Mark's parents come home to find the house in shambles; they blame Helen and have her arrested, unaware that Mark lies dead upstairs. Susan (secretly) dons her late brother's glasses and proceeds to listen to his Nazi music...and the cycle begins anew.