Kriemhilde Steiner was a Nazi agent for the Black Science division. Her mission was to find the "Eagle of ultima Thule", a legendary source of energy searched by the Reich.
On 30 November 1936, going under the identity of "Dr Sophie Renard" of the Societe Archeologique, she found the London pneumatic railway with the help of the Eleventh Doctor, along with the energy source, actually a phoenix egg. After a short brawl with the Doctor and Rory, she touched the egg that hatched, burning her and setting on fire the Crystal Palace above the railway. (COMIC: The Eagle of the Reich)