The Sinner Season 2 begins with a crime as gruesome as it is inexplicable. A young boy named Julian (Elisha Henig) poisons two people assumed to be his parents with gypsum weed. And just as it was with the crime that opened Season 1 of The Sinner, the key question here is not who committed the murder, but why? An early clue to The Sinner Season 2 comes from flashbacks during the premiere episode in which a woman named Vera, played by Carrie Coon, talks to the child about a "Shadow Julian." The first step to figuring out why Julian killed may be to determine what exactly she means by that.
Viewers don't hear much about Shadow Julian in the season's first episode, but it's implied that it's the term that Julian and Vera use to talk about Julian's darker impulses. This is supported by a specific piece of luggage seen amongst the belongings of Julian's victims — who, it turns out, aren't actually his parents. The deceased couple may not have packed anything for their "child," but they do have multiple books from noted psychoanalyst Carl Gustav Jung. Jung wrote extensively about the idea that every human being has a "shadow," which is surely not a coincidence in this case. While it's not yet certain what exactly Vera and Julian are talking about when they talk about Shadow Julian, it seems that this season of The Sinner is going to be referring to Jungian psychology in its exploration of why people commit unspeakable acts.
In his book Archetypes and the Collective Unconscious, Jung puts forth the idea that "the shadow personifies everything that the subject refuses to acknowledge about himself and yet is always thrusting itself upon him directly or indirectly — for instance, inferior traits of character and other incompatible tendencies." Jung explained during a 1937 speech at Yale University that the "less [a shadow] is embodied in the individual's conscious life, the blacker and denser it is," per The New York Times.
Vera's definition of Shadow Julian seems to line up almost perfectly with the Jungian concept of a shadow. Julian talks about how Shadow Julian begins to awaken under duress, and Vera encourages Julian to become one with his shadow self, saying, "Shadow Julian is Julian — is you." Vera asks, "And when he comes knocking, what are you supposed to do?" to which Julian responds, "I let him in." This approach also seems in line with Jungian psychology, as Jung proclaimed, "If [the Shadow] is repressed and isolated from consciousness, it never gets corrected. It is, moreover, liable to burst forth in a moment of unawareness," also according to The Times. While Jung encouraged people to accept and embrace their shadow selves, Julian engaging with his "shadow" may be what pushed him to kill.
Vera's actions and beliefs seem to be rooted in Jungian psychology, but The Sinner suggests that she may be twisting Jung's language to fit her own purposes. Jung encouraged others to not suppress their shadows, yet he also never actively encouraged people to commit immoral acts, let alone murder.
The Sinner introduced many puzzles in its season premiere, and while not all of the answers can be found in Jung's writings, those hoping to understand the themes of the season may want to brush up on his work to better understand how the Shadow-self works.
