- For other people named Davis, see here.
Lt. Davis was a U.S. Navy officer assigned to an Antarctic weather station. While giving the Third Doctor a guided tour, a crewmember of a missing nuclear submarine stumbled into the base and managed to get out a warning before dying of exposure. When the Doctor and Davis left the base to investigate the mystery, a group of Daleks and their human slaves attacked and destroyed the base.
Returning to the flaming ruins, the Doctor and Davis followed the tracks to the Daleks' underground base, where they had been capturing ships and their crew for 300 years. The Doctor and Davis took an old biplane and flew it to a weather ship, where they were unable to warn of the Dalek threat in time. After the Daleks attacked Sydney, Davis worked with the Doctor to defeat their plans, and when the Doctor lured the Daleks underneath a bridge, Davis dropped a live wire onto the sub, electrocuting and killing the Daleks. (TVA: *Sub Zero)