In the second episode of the six-part story "Fury From the Deep," the Doctor (
Patrick Troughton) tries to solve the strange disappearance of several oil-refinery crews from a North Sea drilling site. Halfway through the episode, it is revealed that two of the refinery scientists -- Quill (Bill Burridge) and Oak (John Gill) -- are not quite human, and most certainly up to no good. Written by Victor Pemberton, "Fury From the Deep, Episode 2" originally aired on March 23, 1968. Except for a brief vignette showing Quill and Oak disposing of a victim by exhaling toxic gas, this episode no longer exists. ~ Hal Erickson, All Movie Guide