Sally Arnold

Sally Arnold was scientific researcher at a secret UNIT facility. Working with her assistant Janice and storehouse archivist Graham Winslet, 'Sal' had rediscovered a Nestene pod placed in storage many years earlier. Unaware of the dangers involved, she had tried to activate the fragment and was unsuccessful until she exposed it to deep-space transmissions. Re-establishing contact with the Nestene Consciousness, the creature killed Janice before escaping. With the building placed under quarantine and searched by UNIT operatives led by Lockwood, Daniel Matthews and Sergeant Ramsay, Arnold helped the team find a hidden room containing more Nestene pods and also 'Doctor John Smith's UHF transmitter from a previous encounter (DW: Spearhead from Space). However, though the transmitter was useful in destroying the original pod, unsealing the doors allowed the reactivation of a second pod and also of the Autons still held in the warehouse. This second pod was able to escape through an air vent and evade capture for a further two years. (BBV: Auton)

Joining Lockwood's team in an attempt to rectify her mistake, Dr. Arnold was prevented from taking an active part in the UNIT operation on Sentinel Island, where the escaped pod had re-energised and taken over the island community in an attempt to revive ancient Nestene creatures buried beneath the Earth's surface. (BBV: Auton 2: Sentinel) In the aftermath of the confrontation there, Sal was taken to Millhampton by Ross Palmer to try to locate Lockwood. There, she finally learned the truth about Lockwood, just as his death prevented the Auton take-over. She returned to her UNIT office, furious at Palmer's deception. (BBV: Auton 3: Awakening)