Eric Stahlmann

Director Stahlman was a version of Professor Eric Stahlman from a parallel universe visited by the Third Doctor.

Unlike his bearded counterpart in the primary universe, Stahlman was clean-shaven and wore dark-tinted spectacles. He also spoke in a colder, cooler tone as well as being willing to commit murder by proxy in Sir Keith Gold's case so as to prevent his project from being interfered with.

Stahlman headed the Inferno Project, aided by the Republican Security Forces. He refused to accept the project was failing. He became infected by Stahlman's ooze and mutated into a Primord. He was killed by Greg Sutton with a fire extinguisher. (TV: Inferno)

Behind the scenes
Stahlman's name is spelled with two "N"s on his nameplate, which reads STAHLMANN. However, in the credits for episode five, as well as in the novelisation, it is written as "Director Stahlman". We consider the aforementioned "Stahlmann" spelling to be a production error.