Charlie Duffy was a human activist from Kandoka who got a job at Kerb!am as a cleaner.
However he wasn’t happy with only 10% of the human population getting jobs, so he created deadly bubble wrap, which exploded on contact, and staged a movement where thousands of Kerb!am Men would teleport deliveries of bubble wrap to kill people, so the machines would get the blame, thereby eroding people’s trust in automations and putting the systems out of business whilst more humans would be employed.
Charlie had not intended to fall in love with worker Kira, but he was frequently tongue tied when around her; she seemingly reciprocated his crush on her. He was genuinely devastated when she was killed by the system.
Charlie was an expert in cybernetics, explosives and teleportation, which helped make his plan possible.
When the Thirteenth Doctor ordered the Kerb!am Men to detonate the contents of their packages to foil Charlie’s plan, Charlie was on the floor amongst them. Despite The Doctor and Graham’s effots to convince Charlie to come with them, Charlie stayed on the floor and was killed in the explosion.
While his plan had failed, his actions had convinced Judy and Slade to reorganise Kerb!am to be more reliant on a human workforce.