Billy Callahan

Private Billy Callahan was a soldier who worked on a British Army base in Cambridgeshire where experiments were being performed on prisoners using Stahlman's ooze to turn them into Primords, with the aim of creating a biological weapon. Callahan was uncomfortable with the experiments being performed. When Jo Grant and Brigadier Alistair Gordon Lethbridge-Stewart came to the base to investigate the disappearances of allegedly escaped prisoners, he was very nervous when speaking to them. Noticing his discomfort, Jo and the Brigadier met with Callahan and convinced him to let them into the base so they could learn what was happening. He agreed, but was caught by his superior, General Sharp. As punishment for his actions, Callahan was turned into a Primord. (AUDIO: Primord)