He was portrayed by Ian Fairbairn.
Bromley was a scientist working at the Inferno Project. He was good friends with Harry Slocum. While working in the power station for the project's nuclear reactor, he was attacked and knocked out by Slocum, who had begun to turn into a Primord. After recovering, Bromley turned into a Primord himself, as did UNIT soldier Private Wyatt.
The two roamed the grounds outside of the facility. Although Wyatt died while attempting to attack the Doctor, Bromley hid and remained at large for the duration of the incident. Only when the Doctor returned from the alternate universe did Bromley reappear and attack him. The Doctor was able to grab a handy fire extinguisher and spray Bromley with it, subduing the Primord. His fate after this is not known.
When the Doctor arrived in the alternate universe, Bromley was already transformed into a Primord. He was one of the first individuals the Doctor encountered. As he would later in his own universe, he subdued Bromley by spraying him with a fire extinguisher. Bromley survived, and was captured by RSF forces after being tranquilized. He was put into a holding cell next to the Doctor's.
The tranquilizer soon wore off, however, and Bromley killed the guard and bent the bars with his bare hands, and got into the adjoining cell, where he attacked the Doctor. The Doctor knocked Bromly down with a mattress and used the dead guard's keys to unlock the cell door. He escaped and locked Bromley in, but the transformed technician just bent the bars again and got free. In the control room, he was shot by Brigade Leader Lethbridge-Stewart, but didn't immediately succumb to his wounds. Only when sprayed again with a fire extinguisher by the Doctor did he finally collapse and die as a result of his wounds.