Impersonating Salamander, the Doctor infiltrates the research centre, but Benik becomes suspicious. Underground, Salamander's deception is discovered.
See all episodes from Doctor Who
See all broadcasts of Episode 5 (1)
Give it a go now!
Rebuild, rewire and recode your own Dalek in the new desktop game!
See the behind-the-scenes videos, interviews, clips and other goodies!
Sign in to the BBC, or Register