S4, E5: As poison gas suffocates the Earth's population, the Doctor and UNIT team members work to eliminate the threat. Part 2 of 2.
Starring Freema Agyeman, Billie Piper, Biddy Hodson
S4, E5: As poison gas suffocates the Earth's population, the Doctor and UNIT team members work to eliminate the threat. Part 2 of 2.