Back door to death

the long version

Home Sweet Homicide When lovely young Theresa Graham wed Clifford Hardin, she didn't realize she was marrying his family as well. But their honeymoon visit to the Hardin home proved otherwise, and Theresa felt family ties tightening into a stranglehold. There was mother Hardin, so sweet, so evil...brother Sam, his genius twisted by a secret torment...sister Judy, whose ravishing beauty could not conceal her terror.... Then suddenly, there was murder, and Theresa had no place to hide, no one to trust, and only a dangerous intruder offering help.