The Pale Man was a C19 operative who had been modified with Cyberman technology. He functioned as the liaison between the side of C19's official operations (such as liasing with UNIT and running the Glasshouse) and its "darker" side, such as the the Vault. He also was the point of contact for operatives outside of C19.
Prior to joining C19, he lost his arm in an unspecified accident. He was recruited with the promise of a prosthetic replacement, but the actual procedure replaced all his limbs and his internal organs. Due to his partial cyberconversion, he was approximately ten times stronger than a normal human. He was also superhumanly fast. As a byproduct of his conversion, he lacked a sense of taste. He had stopped ageing, but still required food and drink to keep his head and facial skin looking healthy.
He was pale, with a scar on his face, and hid the fact that his eyes had been replaced with microfilament discs behind silver-rimmed sunglasses. He invariably wore a light grey suit.
He killed Grant Traynor with the Stalker when Traynor threatened to expose the secrets within C19. Later, he sent a blond man to assassinate the Third Doctor, but this failed when the Doctor was taken to the Silurian shelter on the island of L'Ithe. When the Doctor was found and brought to the Vault, the Pale Man revealed he intended to use Silurian DNA to create a race of super soldiers to take over Earth, but was stopped when UNIT troops infiltrated the Vault. He escaped being captured. (PROSE: The Scales of Injustice)
The Pale Man later manipulated one of the UNIT soldiers who survived the Axos invasion to capture the Brigadier. He also revealed that his real name was Martyn Townsend, and tried to change his deteriorating condition by converting to the body of an Auton. He failed in this plan and he died. (PROSE: Business Unusual)