Nothing is known about Duncan's life prior to or as the outbreak began.
Upon Maggie and her group's return to Alexandria after their mission at Fort Connors, she is overjoyed to see that Duncan, along with Agatha and Frost, are alive and well. He playfully greets young Hershel and hoists him on his shoulders as the group talks. Later during a meeting, Maggie explains that Duncan, Agatha, and Frost were separated and believed to have been killed after Reapers attacked their village. Duncan and his fellow Wardens agree to accompany Maggie and a group of Alexandrians to Meridian to take out the Reapers and secure the food and water supplies to feed everyone in Alexandria.
Part of a group consisting of Maggie, Daryl, Alden, Cole, Elijah, Gage, Negan, Agatha, Frost, Roy, and Gabriel, the survivors utilize Negan's familiarity with the DC area to travel to Meridian. Due to the heavy rain storm, the survivors are forced to head into the subway tunnels to complete the journey. While in the tunnels, they come across hundreds of body bags, many containing walkers in them. At some point while dispatching the body bag walkers, Gage and Roy go missing, along with the group's ammo and supplies. Shortly after this realization, a large group of walkers appear, forcing the other survivors to move forward in the tunnel without being able to search for Gage or Roy. He is able to make it into a subway car before the walkers are able to catch up with his group.
Duncan will appear in this episode.
After the Reapers attack his group, Duncan attempts to defend himself and avoid getting killed, but he gets wounded by the throwing knives. With the members fragmented into smaller groups, Duncan and Agatha manages to escape alive. Later, they arrive at the building where Maggie meets up with them. Duncan's wounds are too severe and he implores Maggie to get Agatha home safe before dying, and Maggie puts him down.
In a brief flashback to the beginning of the previous episode, Duncan can be heard again, shouting for the others to run from the Reapers, just before Daryl takes off on his own.
- Killed By
Duncan is stabbed several times by the Reapers' throwing knives. He is able to escape the attack with Agatha. After some time, he bleeds out from his injuries, but not before saying his final goodbye to Maggie. Afterwards, Maggie stabs him in the head so he doesn't reanimate.
This list shows the victims Duncan has killed:
|✔||Appears||✔||Voice is heard|
|👁||Appears with no lines||✔||Appears in a flashback|
|✔||Appears as a walker||🖼||Appears in a photograph/video|
|✔||Appears as a corpse||✔||Appears in a hallucination/dream|