Netflix is going behind the gruesome headlines.

The hair-raising trailer for a new true-crime documentary dropped Wednesday, and the streaming giant is digging into the sick tale of Chris Watts, the Colorado dad who was convicted of killing his wife, Shanann, and their two young daughters.

“American Murder: The Family Next Door” premieres on the platform on September 30.

Thirty-four-year-old Shanann, who was 15 weeks pregnant, 4-year-old Bella and 3-year-old Celeste went missing in August 2018. Days after they were feared “endangered,” Chris was arrested and confessed to the killings. Their bodies were soon recovered in an oil tank. In November 2018, he was sentenced to life in prison for the crimes after pleading guilty.

“Using raw, firsthand footage, this documentary examines the disappearance of Shanann Watts and her children, and the terrible events that followed,” the doc’s description reads on Netflix.

The new trailer features footage from Shanann’s YouTube channel, where she often discussed her seemingly blissful marriage with Chris. Viewers will also get to see clips taken during the initial investigation after the family went missing, security-camera video and Chris in the interrogation room.

“There’s only one person in this room who knows what the truth is — and in about five minutes, there’s going to be two of us,” an investigator tells Chris in the emotional promo, which is interspersed with video from the Watts’ wedding.

“We’re not promised tomorrow,” Shanann is heard saying in the haunting trailer.  “We’re not promised anything.”