蘭斯林（丹尼斯·奎德 Dennis Quaid 飾）警官同時也是一個單身父親，因公務繁忙，他無暇照顧兩個兒子，大兒子亞歷克斯無形中時常扮演父親的角色。最近蘭斯林被一樁連續殺人案纏住，每個兇案現場都發現了至少四名嫌疑人的蹤跡，并且統一留下了“過來看”的血色留言，死者死于懸掛的狀態充滿了宗教意味，蘭斯林從人體懸掛的鐵架入手，發現這一干罪犯以殺人作為宗教儀式，并且以啟示錄中記載的“天啟四騎士”自居。第一個受害者的華裔養女克里斯汀（章子怡 飾）主動找到蘭斯林，坦承了自己與連續殺人案的關系，但是這不能阻止更多人受害，蘭斯林驚見自己最不愿意看到的事情發生了……

　　Sheila Hood is an ex-cop whose marriage is on the rocks. Rather than confronting her husband about an affair, she hides surveillance cameras in her home and watches his transgressions, becoming a voyeur of her own life. Her husband, Tom Kale, is an ornithologist who begins an affair with an ex-girlfriend, Merle James, whose beauty and fragility echoes that of the birds he studies. Ray Starling, the charismatic owner of a boutique hotel, is Merle’s lover, and has dealings with her father, Mr James, a powerful oil baron who operates in the shadows but whose influence touches the whole city. Merle’s younger sister, Hazel, is also drawn to Tom, but trapped in Starling’s web of power. Calvin is an cop whose loyalty to his ex partner, Hood, is tested when mounting evidence from her own surveillance tapes connects her and Tom to Starling’s murder, and perhaps even Merle’s mysterious death.

 伊薇（尼娜·凱莉 Nina Kiri 飾）肩負著照顧臨終母親的重任，她渴望逃離支離破碎的現實帶來的孤獨感。如今，她住在一間堆滿感傷紀念品和回憶的房子里，理智和生活秩序都維系在她制作的超自然播客節目《底音》上。雖然她通常對搭檔賈斯汀發給她的那些令人毛骨悚然的音頻文件持懷疑態度，但最新收到的音頻卻讓她感到不同尋常。一對年輕備孕夫婦的十段從未公開錄音逐一揭曉，每一段都比上一段更加不祥。隨著伊薇將這些錄音與她目前的遭遇進行對比，隱藏的信息逐漸顯現，將她推向瘋狂的邊緣……