Galloway was a prisoner of the Daleks.
Along with Stien and several other prisoners, Galloway escaped to London 1984 via a time corridor. However, two Dalek Troopers disguised as policemen came to London after them and killed all the prisoners except for Stien and Galloway, who both managed to take refuge in an abandoned warehouse. Galloway went to investigate one of the top floors, but was shot and killed by a Dalek Trooper. (TV: Resurrection of the Daleks)