Although he only appeared in two episodes, Edwin was shown to be a highly intelligent, determined and caring person who was dedicated to his career as a doctor and was also a loving husband to his beloved wife, Candace. It contrast to his colleges who either fled the CDC during the start of the outbreak or took their lives, Jenner chose to stay behind and work for as long as he could, although it was later revealed that he only did this at his dying wife's request, not because he wanted to.
Despite being safely sheltered from the apocalyptic hell occurring outside the CDC, Jenner was extremely well aware of the utter horrors and cruelty of the new world and viewed it as being mankind's extinction event and that staying alive was pointless as a painful death was inevitable. Jenner believed so strongly in this that he attempted to trap Rick and his group in the failing, set-to-detonate CDC complex to offer them a peaceful death, although after hearing their protests to try for as long as they could, Jenner agreed to give them a chance and before meeting his demise, along with Jacqui, appeared pleased that the group managed to escape.
Dr. Edwin Jenner worked alongside his wife, Candace Jenner, at the Center for Disease Control (CDC). He knew a fair deal about the building and facility as well as safety protocols and decontamination steps. He also interacts with the CDC's main computer Vi who helps run the facility as well.
Dr. Jenner was seen making video log entries about his work and research while working with samples in order to find a cure. On day 63 of the global outbreak, after starting the day's work to find a cure, Jenner reached for something and accidentally tipped a vial over, the contents of which landed on the exposed sample. This caused toxic fumes, causing the lab to go into a full decontamination mode which destroyed the remaining sample. In despair, Jenner decided to get drunk on wine and was contemplating shooting himself in the head. When the Atlanta group showed up at the CDC's doors, he reluctantly let them in after watching survivor Rick Grimes face the security camera and beg for someone to let them in.
Edwin met the survivors in the lobby of the CDC and demanded a blood test from all of them to check if they have been infected, saying that it was standard procedure and locked down the front doors permanently. After clearing everyone, he invited them to make themselves comfortable, showing that they had electricity, food, beds, and hot water, all amenities that the survivors have not had for a long time.
Later, everyone dined with Edwin and they bombarded him with questions. In answer, he brought the group to the control room and talked about the CDC and how he was the last one alive after the rest of the doctors and staff committed suicide - as Jenner put it, "opting out...".
From the control room, Jenner showed the Atlanta survivors a video of "Test Subject 19's" brain, which offered a picture of the infection and how it affected a person's brain before, during, and after death. It was later revealed that TS-19 was his wife, Candace, the head of the CDC who was infected and devoted her failing body to research in an attempt to find a cure.
When Dale Horvath asked about the countdown timer on the wall, Dr. Jenner replieed that it was counting down to when the generators in the basement would run out of fuel, prompting an explosion set to destroy the entire CDC. Jenner then closed the doors to the computer lab. The survivors panicked and attempted to flee, but Dr. Jenner sealed the exit doors of the control room, reminding them of his words when he let them in ("When I close those doors, they won't open again."). He claimed that it was no use anyway since he could not do anything to open the doors to the outside. This caused outrage from the trapped group. He tried to comfort them, saying that the explosion would be peaceful and virtually instantaneous, and Shane attempted to kill him.
Jenner relented after Rick and Carol made a passionate argument and unlocked the control room doors, allowing the survivors to try and find a way out. Before Rick left with the rest of the survivors, Dr. Jenner whispered something inaudible to the audience into his ear. Jacqui was the sole member of the Atlanta group who decided to stay behind with him as the building explodes. Andrea also decided to stay, but Dale convinced her to come with the rest of the group.
- Vi (Caused)
- Himself (Suicide)
With the loss of his wife, after using her samples to possibly develop a cure, and the mass power failure, Edwin gave up hope and decided to commit suicide. He said that it was the most peaceful way to die, with no pain or suffering and in the arms of the ones that we love and care about. With the CDC building losing power, Vi deployed the HITs to prevent any diseases (and people) from escaping and decontaminated the entire facility.
This list shows the victims Edwin has killed:
- Candace Jenner (Zombified)
- Himself (Suicide)
- Jacqui (Assisted Suicide)
- Possibly numerous counts of zombified patients
- "I made a promise. To her... my wife."
- —Edwin to Rick[src]
It was revealed that Edwin loved his wife very much, and had promised her (before her death) that he would go forward in studying the virus and perhaps discover a cure, which is why only he had remained in Center for Disease Control.
- "You don't know what's it's like out there....you may think you do but you don't."
- —Rick to Jenner[src]
Jenner seemed to trust and care about Rick's group, as he let them inside the CDC, providing them with food, showers and most importantly, shelter. He also warned Rick about everyone being already infected. It is possible that he did this out of a sense of guilt and obligation to help people in every way that he could after failing to create a cure for the zombie plague. However, Rick wasn't sure to believe him or not and kept it from the group out of concern. After seeing Shane reanimate, Rick finally realises Jenner was right. Though he seemed willing to keep Jenner's last words secret, still he eventually confessed after people grew suspicious about Randall turning without being bit.
Edwin and Dale had a stable relationship and got along very well while the group was hosted in the CDC. During their stay, Dale asked a lot of questions to the doctor about his work in the building.
Edwin and Andrea had a stable relationship and get along very well while the group recieves shelter at the CDC. Both shared the loss of a family member to each other, and Andrea was one of the few members of the group who was in agreement with Jenner, that there was nothing left outside in the world and that survival was pointless. Andrea was later angry at Dale for not letting her take Jenner's offer of a way out.
- The name Edwin Jenner is a nod to Dr. Edward Anthony Jenner, the English researcher who discovered the smallpox vaccine in 1796.
- In The Walking Dead: Survival Instinct, at the Atlanta football stadium where the evacuation is taking place, radio communications can be heard from the first helicopter taking off stating that a person named "Jenner" has been evacuated.
- The episode title "The Day Will Come When You Won’t Be" is a reference to Edwin's words to Rick after he thanks him for saving his group's lives by allowing them into the CDC.