A successful lifestyle entrepreneur is happily pregnant and awaiting the arrival of her first child. But soon after Jo welcomes baby Ruby home, something starts to feel off - even though she's assured it's all perfectly normal. As Jo fights to protect herself and her baby, she is plunged into a waking fever dream where everyone is a threat and nothing is what it seems. At last, she must confront the truth of her own darkness and contend with the ultimate human sacrifice: the one mothers make for their children.