Katie Langdon is a call handler who works at the Wyvern Ambulance Service Communications Centre.
In April 2019, Katie became engaged to her boyfriend Jay who was a first responder. However, when attending an incident at Milford Warehouse, he crashed his motorcycle whilst trying to avoid hitting police officer Rox Adams. He sustained an open fracture, and, at the hospital, Katie was told that his leg required amputation. As a result, they were forced to postpone their engagement party. Two weeks later, Katie desperately tried to convince Rox not to kill herself, but she failed to get through to her and allowed Iain to take over the call (CAS: Episode 1125)