At the intimate house-warming party for her glorious 'grand design', Kathleen confides in her best friend Beth that she is terrified of one of their close friends, but daren't reveal which one. The guests are a tight-knit group, but Kathleen is convinced one of them is dangerous. The next day Kathleen's body is found at the foot of a cliff and Beth must face the sickening truth that she may have been killed by one of their trusted friends. With little help from the police, Beth's decides to seek answers. All the friends have secrets they are desperate to hide, but only one of them is ready to kill to keep theirs safe...