What happens between Jurek and Karl? 'Nocturne' episode 1 and 2 ending explained
‘Nocturne’ has released its first two episodes as the series opens with a disturbing connection between a convicted serial killer and a psychiatric hospital worker. 6 months after the man previously locked up beside Jurek dies, Karl is moved to the restricted housing unit (RHU), where Jurek is the only permanent resident. Karl is warned not to listen to Jurek or reveal anything about himself.
However, Jurek gradually finds ways around these restrictions. He gets a nurse to reveal Karl's favorite song, persuades the nurse to secretly mail something to his lawyer, and manipulates another nurse into appearing guilty when the unit director begins to question the situation.
Felicia disappeared three years ago alongside her brother, Michael Frost. Authorities eventually find Michael, but Felicia remains missing. Jonah, who worked on the original case, suspects Jurek had an accomplice. Michael describes a woman who matches the description of Jonah's former partner's wife. The woman went missing after Jurek's initial arrest, strengthening Jonah's suspicion that the killer had an accomplice.
Jonah and FBI agent Quinn (Poorna Jagannathan) visit Jurek at the psychiatric hospital. He claims to know who took Felicia but demands a truth-for-a-truth exchange. His request puts Jonah in a difficult position and forces him to revisit his troubled past with the killer.

Saga decides to enter the psychiatric hospital and get close to Jurek. She believes she can gather information that Jonah and the FBI cannot obtain from outside. Jonah struggles with her decision. Jurek has already cost him a partner and a friend, and he fears losing someone else. Although he accepts that Saga is the right person for the assignment, he insists on precautions.
Only Jonah, Quinn, and Nathan (Gary Carr) know about her undercover operation. Saga wears a micro-transmitter hidden inside a cross necklace, allowing the team to monitor her conversations inside the hospital. Her confidence in her training also reflects her complicated relationship with Jonah and her reluctance to show vulnerability.

Stephen Graham explains that Jurek recognizes Karl's vulnerability and uses it to gain his trust. Karl finds Jurek fascinating and believes he can help him. Rory Culkin describes his character as someone who genuinely wants to help people. He sees a strange mix of danger and gentleness in the convicted killer.
Jurek once throws him against a wall but then lets him go and asks for help. These conflicting actions make Karl increasingly curious about him. Co-showrunner John Hlavin credits Graham and Culkin for shaping the relationship. Director Tim Van Patten brought the actors together for a rehearsal before the table read.