In the eighth episode of Dead Boy Detectives, a startling revelation awaited Crystal. She discovered that she hailed from a wealthy family, one where her parents were neglectful and she herself was, frankly, a rather unpleasant individual. Such revelations, however, were hardly surprising.
Meanwhile, Esther embarked on a dark experiment, torturing a ghost within her newfangled machine to extract its power. As the ghost vanished into oblivion, Edwin became her next target.
Crystal reached out to her estranged parents, who were blissfully unaware that their daughter had been missing. Consuming another memory ball, she realized that she must return home to confront the truths she had never known. As Niko and Edwin, close friends, prepared to depart for London, Crystal bid them a heartfelt farewell.
Jenny, finally emerging from her slumber, was introduced to the world of demons and ghosts by Crystal and Niko. They revealed the sprites trapped in the jar and, astonishingly, Jenny could now see Edwin and Charles as well.
Amidst these revelations, Crystal bade farewell to everyone and departed. But her departure was short-lived as a deafening explosion rocked the butcher shop. Esther was revealed as the culprit, having caused the destruction and captured the two boys. Determined to save them, Crystal and Niko set out on a perilous journey.
They sought the wisdom of the cat king, hoping to gather information about Esther. The king recounted the tale of Esther's transformation from a beautiful and hardworking woman to a witch. Betrayed by her husband, she turned to black magic and murdered him. Desperate for immortality, she invoked the ancient goddess Lilith, who granted her wish but at the cost of her youth. To maintain her young appearance, Esther fed young girls to a monstrous magical snake.
Armed with black salt provided by Tragic Mike at the magic shop, Crystal and Niko bravely confronted Esther at her lair. They threw Charles's infinity bag to him, tasking him with slaying the snake. Monty, transformed into a crow, assisted Charles in breaking free from Esther's iron shackles.
Meanwhile, Esther tormented Edwin, extracting his pain to fuel her powers. But the black salt seemed powerless against her. In the chaos that ensued, Niko valiantly shielded Crystal, ultimately sacrificing his life to Esther's merciless attack.
Desperate to save the day, Crystal delved into Esther's mind, invoking the goddess Lilith. She revealed Esther's sordid secret - the sacrifice of young women to preserve her youth. At the same moment, Charles engaged in a furious battle with the snake, ultimately vanquishing it. Esther's true form emerged as Lilith appeared, dragging her away as punishment. Edwin was saved, but the cost was Niko's life.
Back at Jenny's, they learned that Niko's body would be returned to Japan. Crystal extended an invitation to Jenny to join her in London, which she pondered. Edwin bade farewell to the cat king, parting on amicable terms and sharing the correct count of cats in the city.
At the Dead Boy Detectives' London office, the Night Nurse and her superior arrived to reclaim the boys for the Afterlife. However, her superior recognized the countless lives the boys had saved and granted them permission to remain on Earth, solving mysteries. As their overseer, the Night Nurse was reluctantly assigned to accompany them, much to her dismay.
In a poignant epilogue, a mysterious figure held Niko's lucky charm, hinting that perhaps his soul had not truly departed for the Afterlife. And so, the first season of Dead Boy Detectives drew to a close, leaving viewers with unanswered questions and a lingering sense of sadness.
