The Bronze Brotherhood, lead by Reginald Dominic Huberton III, represents the interests of those who invested in the mad scientist's machine. These interests were less than pleased when, instead of an easily controlled private portal, the scientist constructed the machine ahead of schedule in the middle of a public square, leading to the English government promptly assuming control of its use and practically beggaring the investors as a result.
Practically. Not that any of them were reduced to begging- but the indignity of adjusting ones fortunes around such a blatant betrayal is not easily forgotten, and these fine people want their due.
They intend to regain control of their property (the portal) and use this control to manage trade. Their current avenue of research re: control of the portal is the amassing of magnetic iron, as it appears that the colony-side portal often manifests in areas of unusual magnetic activity. This research is facilitated by the Bronze Brotherhood's immense wealth in the form their employees' technical and scientific expertise, and Huberton's personal ownership of the manufacturing company responsible for the EZ-ARRM.
The Bronze Brotherhood is tends to use the colors violet and bronze as a method of identification. They are based out of a truly impressive airship known as the Bronze Behemoth that employs uniquely effective robotic guards. They possess a talented spy network that has infiltrated nearly every aspect of society on the colony, and has significant footholds in England. Given their extensive resources and personnel, it seems it is only a matter of time until they achieve their goals.