The body of a young man is brought into the Coroner's office and David is about to perform an autopsy when the dead man gets up and walks out the door. Our CSIs investigate how a man pronounced dead can turn into a walking zombie. Just as the investigation get started another young man is found dead in an alley. When Sara arrives, this dead man has also seemingly come back to life and walked away from the crime scene. The team finds in zombie #1's possessions a notebook written by a disgraced professor from WLVU who was fired more than 20 years ago after he was deemed to have contributed to the death of a student. Dr. Aden explored the existence of the hereafter and had encouraged his students to take substances that would get them closer to the afterlife. Sara and Langston work with the eccentric professor to try and figure out what these young men, who were students at WLVU, were doing with Dr. Aden's book. They discover the students, Max (zombie #1) and Kurt (alley zombie), were documenting there attempt to take a lethal poison which would cause paralyzes and slow their heart rate so they could get close to the afterlife and then return to tell the tale. Our CSIs soon find Kurt was killed by Max after he confronted him about the poison he was given. The team finds Max but he is still in a drug induced state and runs. He jumps in front of a minivan and is instantly killed which leaves our CSIs with more questions than answers. A third female student was also missing and part of the experiment. We find that she was actually the mastermind behind the experiment and had reached out to Dr. Aden 6 months prior, after her mother's death. Dr. Aden lied to the team and they track him down to confront him and hopefully find the female student. What they find is Aden has taken the poison himself to finally reach the afterlife but is too far gone for the CSIs to bring him back. Through evidence in his home, they find the female student alive, claiming to have seen the other side and her mother. Her joy about finally reaching her goal is destroyed when she finds out her two friends are dead.