Sara Howard (Dakota Fanning) has struck out on her own in “The Alienist: Angel of Darkness” — she’s running a detective agency and her help is sought when a child goes missing. She’s soon leading a case investigating a serial killer preying on children, a new trailer for the “Alienist” sequel reveals.

“The police are not interested in finding your child,” Sara tells the family of missing infant Ana Linares. “This is why we called upon you, Sara,” her client replies.

Sara is the one calling the shots in “Angel of Darkness,” but she also depends on the help of her “Alienist” colleagues, criminal psychologist Laszlo Kreizler (Daniel Brühl) and journalist John Moore (Luke Evans).

“There is a violence to this case, a fury,” Laszlo tells Sara, but she remains undaunted. “No matter the criminal’s stealth or genius, there is always a trail,” she says. “I will move heaven and earth to find the child.”

No wonder one character describes Sara as “a renegade in a corset.”

“The Alienist” aired on TNT in 2018.

“Viena and the Fantomes,” “Sweetness in the Belly,” and “Once Upon a Time… in Hollywood” are among Fanning’s recent credits. She’s set to star with her sister, Elle Fanning, in Mélanie Laurent’s adaptation of Kristin Hannah’s best-selling WWII novel “The Nightingale.” Fanning directed a short, “Hello Apartment,” for Miu Miu Women’s Tales 2018.

“The Alienist: Angel of Darkness” will have a two-part premiere on TNT July 19. Two episodes will then air each Sunday.