Dakota Fanning as Sara, Daniel Brühl as Kreizler
In a sneak peek from Season 1, episode 4 of TNT’s “The Alienist,” Kreizler (Daniel Brühl) tries to explain to Sara (Dakota Fanning) that every people has the capacity to kill. TNT/Kata Vermes

Kreizler tries to make Sara realize that everyone has the ability to take someone’s life.

In a sneak peek from Season 1, episode 4 of the TNT’s “The Alienist,” Kreizler (Daniel Brühl) tells Sara (Dakota Fanning) that she’s not that different from a young woman sitting on the other side of the park.

“Do you see that woman there?” Kreizler casually asks Sara as they sit on a bench at the park. “She’s from a good family. She was soon married and quickly gave birth to a boy, and a year later a boy.

When Sara asks Kreizler what he’s trying to point out, the doctor says that he’s attempting to make her realize that she’s “quite similar” to the young woman.

Sara quickly reminds Kreizler that unlike her, the young woman is married and has two children. Kreizler then reveals that the young woman actually “had children.”

“It was six months after the birth of her daughter, in a seemingly inexplicable act, the young woman herself submerged both her children in a bathtub until they were drowned,” Kreizler reveals. “[But] owing to the wealth and influence of her family, she was spared from being sent to prison or institution. However, instead of proper treatment, she now walks the park daily, pushing an empty perambulator.”

When Sara makes it clear that she finds no empathy for a mother who would take the life of her own children, Kreizler says that she may probably empathize with her as a fellow woman who deals with the same set of expectations from society.

“Do you understand the expectations that our society bestows on women: to marry, to have children, to smile when you’re feeling capable of smiling?” Kreizler asks Sara. “If you can empathize with that you know better than most that that poor young woman with an empty baby carriage did not form herself. Rather society formed her.”

“You say you cannot see yourself from a perspective of a child killer, because you could never kill a child,” Kreizler continues. “[But] I believe we all possess the raw materials required to commit horrible acts. They just need a right or wrong combination of events to make the raw materials combustible.”

In the trailer for the episode, Kreizler and John Moore (Luke Evans) continue to try to find out the motive of the serial killer on the loose. “What we’re missing John, is not how he kills, [but] the why, and most importantly when will he kill again,” Kreizler says of the murderer in the promo clip.

Elsewhere in the hour, as stated in the synopsis, Byrnes (Ted Levine) and Capt. Connor (David Wilmot) keep an eye on a potential suspect. Also, Moore goes on a date, and Roosevelt (Brian Geraghty) finds himself under public scrutiny.

“The Alienist” Season 1, episode 4, titled “These Bloody Thoughts,” airs on Monday, Feb. 12 at 9 p.m. EST on TNT.