Before the outbreak, Robert worked at a power plant called Lonestar Power & Light in Texas where Grace was an operations manager.
When the outbreak began, Grace called in all of the plant's shifts to keep it running, later calling in all of their families when things got worse. Due to the abundance of supplies and the sturdiness of the plant itself, the survivors were able to form a safe community with the plant's walls. However, they lacked the infrastructure to properly maintain the plant and one of the reactors melted down, killing all but Grace. Robert died in the meltdown and became a walker contaminated by radiation that wandered the area around the plant.
While Morgan, Alicia, and Grace were examining the dead walkers at the plane crash site, Robert appeared with a small herd of walkers. Spotting his dosimeter, Grace recognized that Robert was one of her friends from the plant and radioactive, but Alicia hesitated to turn over Grace's gun to her. Alicia decided to deal with the non-radioactive walkers while Morgan and Grace dealt with Robert. However, the walkers all fell into the mud and Robert lost his dosimeter, making it difficult to tell him apart from the other walkers. After Alicia had dealt with most of the walkers, Grace used a Geiger counter on the last two. Determining that one was clean, Grace shot it, causing Robert to turn on her as Morgan set out a tarp behind him. Once the Geiger counter confirmed Robert as the right walker, Grace shot him through the head and he fell back onto the tarp.
Following the fight, Grace wrapped up Robert's body in the tarp and retrieved his dosimeter, adding it to her collection of dosimeters taken from the radioactive walkers she had killed. Morgan realized that Grace knew Robert and the other walkers and she explained the story of what had happened to the power plant. After dealing with the radioactive walkers at Camp Cackleberry, Grace stated that she intended to take all of the radioactive remains to a cavern system near the plant and bury them there so the remains would be of no threat to anyone else.
In a flashback, Grace examines Robert's dosimeter after putting him down.
- Killed by
- Reactor Meltdown (Alive, Off-Screen)
Following the beginning of the outbreak, the survivors at the power plant lacked the infrastructure needed to properly keep the plant going. As a result, one of the reactors melted down, killing all of the survivors at the plant, including Robert and contaminating them.
- Grace Mukherjee (Zombified)
After Robert arrived as part of a small herd, Grace used a Geiger counter to determine which walker was radioactive as Alicia dealt with the rest. After the Geiger counter identified Robert as the correct walker, Grace shot him in the head and he fell onto a tarp Morgan had laid out behind him.
This list shows the victims he has killed:
- Possibly numerous counts of zombies and unnamed people
- "The Hurt That Will Happen" (Zombified)
- Though his name is not given in the episode, it is visible on his dosimeter when Grace examines it.