One Dead Girl follows young and broody Sita's new life as a ghost. Sita is relieved to discover that she is attached to her living boyfriend. Unfortunately, there are many things about the afterlife that Sita has to learn before it's too late.

The most critical aspect of Sita's afterlife is that murdered ghosts must do one of two things. They must haunt their murderer or protect a loved one. They are only allowed to watch over their loved ones if they do not know who killed them. Will Sita find her murderer? Or stay with her boyfriend? Will her boyfriend think she is an angel? Or a demon haunting him?