Lorry driver (The Invasion)

An agent for UNIT, posing as a lorry driver, was working undercover in the International Electromatics compound, and drove out to report back to UNIT.

When the driver was attempting to drive out, the Second Doctor, Jamie McCrimmon and Zoe Heriot stopped him when the Doctor asked for a lift to London. The driver briskly rushed the Doctor and his companions into the lorry, and they briefly hid from IE motorcycle patrols.

When this happened, the driver explained to the Doctor and his companions about IE, and the queer happenings concerning those who got in. The driver ushered the Doctor, Jamie and Zoe away when he stopped the lorry, and just after they left to get to safety, a two-man IE patrol caught up with him.

After checking the driver's pass, the lead patrolman wanted him to come back with the patrol into the IE compound for questioning, but the driver refused, claiming they weren't on IE property and if they wanted to hold him they should get the police. After that, the driver was shot and killed by the two patrolmen.

Later, aboard the C-130 Hercules serving as UNIT's command centre, Brigadier Lethbridge-Stewart showed the Doctor and Jamie photographs of prominent people, all of whom had been to the IE building in London and had either disappeared or "changed" as a result. When Jamie spotted a picture of the driver, the Brigadier explained the man was a UNIT agent and hadn't reported in for twelve hours, but the Doctor doubted anything bad had happened. (TV: The Invasion)