is the 19th episode of the second season of Doctor Who (1963), originally aired on March 6, 1965. It serves as the fourth part of the six-episode serial "The Web Planet" . Plot Overview

The episode continues the struggle on the planet , where the Doctor and his companions are caught between warring insectoid races.

: Ian Chesterton and the Menoptra leader Vrestin fall into subterranean caverns following a cave-in. There, they meet the Optera , a wingless, hopping subspecies of the Menoptra who live in the dark. Ian manages to convince the Optera that they are not enemies from the "above" and gains their help to tunnel toward the Carcinome (the base of the Animus).

: In the Carcinome, the Animus —a malevolent, spider-like entity—uses the Doctor to locate the landing site of the Menoptra invasion force. The Doctor realizes the Animus uses gold to channel its mesmerizing influence and begins working on a way to counteract its control. Production & Legacy "Doctor Who" Crater of Needles (TV Episode 1965) - IMDb