|First Appearance||"Doctor of the Dead"|
|Last Appearance||"Doctor of the Dead"|
|Death Episode||"Doctor of the Dead"|
|Cause of Death||Radiation. Out of mercy by Murphy.|
|Series lifespan||"Doctor of the Dead"|
Brandon Doyle was working as a lab technician in the underground facility in Fort Collins, Colorado.
Working on a bio-weapon named "Red Death," the virus jumps to Brandon and he is infected. Quarantined in the lab by Dr. Marilyn Merch, he is injected with the trial vaccine. It prevents him from turning zombie, but it also prevents him from dying.
Abandoned in the lab at Fort Collins, he was reduced to a rotting torso. He was barely alive but seemingly could not die. He remained intelligent and functional enough to play a video on the monitor above him, by using the keyboard. This revealed what had previously happened to him. It was then that Brandon asked Murphy to "kill him".
Dr. Walter Kurian, posing as Dr. Kurtz, came in accompanied by two armed men. He then threatens Murphy and refers to Brandon as "Patient Zero". Kurian suggested that someone give him mercy and as his soldiers seem to move in for the mission, Murphy quickly volunteered. Murphy cries and tells Brandon that he is sorry for everything that happened to him. Brandon's last words were, "Don't trust him."
After being tortured as a live guinea-pig under Merch and Kurian, he is finally given Mercy by Murphy.