In Intruder, Karen Parker's husband is away on a business trip and she is home alone in a sparsely populated subdivision. They have only recently moved into the house and have not yet installed a security alarm. Also, she feels even more alone because she recently lost her beloved dog to a heart ailment.She is preparing for bed when she hears someone breaking in, then discovers she left her cell phone in her car...and her home phone line has been cut. The intruder succeeds in breaking in, and Karen finds herself in mortal danger. When she locks herself in the bathroom, strange things begin to happen.In Engine Trouble, Kitty Delaney has a fight with her husband and runs home to her mother, who lives a hundred miles away. She has car trouble and stops at a garage on a lonely stretch of highway. She finds that an escaped killer has killed the attendant and takes her as hostage.