The head of security was in charge of security at the Pharos Project.
Biography
The head of security helped his guards apprehend Adric, Nyssa and Tegan after they were seen on the grounds of the Pharos Project on 1 March 1981,
He demanded to know how the companions got onto secure premises, and forced them to lean on the ambulance which had arrived for the newly regenerated Fifth Doctor so they could be frisked for weapons.
Adric managed to distract the head of security and the guards long enough by pointing up to the sky and supposedly indicating the way into E-Space, allowing Nyssa and Tegan to steal the ambulance and use it to get him to the TARDIS.
The head of security managed to hold Adric and ordered his guards to try and get into the TARDIS. However, the Master's TARDIS then materialised and the Tremas Master used energy bolts to knock out the head of security and his guards — allowing Nyssa and Tegan to help Adric into the Doctor's TARDIS. (TV: Castrovalva)