As Dexter recalls his past as a student to hunt down a new victim, he faces a mysterious murder mystery linked to religious motives. On the other hand, Debra turns into a heroine, which opens up new horizons for her.
The criminal department enlists the help of Reverend Sam, who seems idealistic but hides dark secrets. However, Dexter soon begins to get to know him, raising questions seeking to understand his nature.
Dexter is confronted by a ghost from his past, as a serial killer he previously confronted returns, prompting him to reflect on his uncertain future and the impact his actions have on those around him.
Dexter's spiritual crisis deepens, prompting him to seek help from Sam. Moreover, Debra deals with the pressures of her new job and faces challenges at work.
The hunt for the new serial killers, the Doomsday Killers, begins, and Dexter finds himself facing a complicated mystery. The investigation delves deeper into the world of organized crime, revealing shocking secrets.
Dexter's personal life and professional life become dangerously intertwined as he finds himself embroiled in a case that stirs up deep emotions within him. On the other hand, Debra struggles to cope with each assignment she receives.
During a thrilling trip to Nebraska, Dexter meets another serial killer who shares his bloodlust, and this unlikely partnership reveals new sides of Dexter's personality.
Dexter uses the lessons he learned from Brother Sam as he investigates the Doomsday Killers, however, he faces new difficulties when his vision clashes with his co-workers.
Dexter gets closer to catching the Doomsday Killers by receiving help from an unlikely source, but he faces new surprises. Meanwhile, Debra discovers shocking and harsh truths about herself.
The conflict with the Doomsday Killers continues, and Dexter tries to predict their next move before it's too late. On the other hand, Debra faces a personal crisis related to the crime scene and her relationship with her brother.
Dexter resorts to new methods to catch the Doomsday Killers, which puts him in a dangerous confrontation. On the other hand, tensions rise between Debra and her colleague Maria LaGuerta.
The conflict with the Doomsday Killers peaks, and Dexter and his team race against time to save innocent lives and catch the killers. Moroever, Debra faces fateful decisions that will change her life forever.