Not Alone was conceived due to the disappearance and suspected homicide of Sarah MacDiarmid (which is still unresolved), on Wednesday 11th July 1990, from Kananook railway station near Frankston, Victoria.

Sarah enjoyed her sport and particularly tennis so it was usual for her to enjoy a game on Wednesday nights each week with friends from work. Wednesday 11th July 1990 was no exception and after enjoying her tennis with three other friends from work, they stopped for a drink prior to going home.