Tatiana Kregki

 was a Russian fighter pilot in the Soviet Air Force during World War II, and was the top pilot of the Night Witches. Physically, she was the exact double of the Doctor's companion Polly Wright.

Early life
Tatiana was born in Meshino, a long way south of St Petersburg. Her father was the manager of the local theatre, and he wanted his daughter to become a music hall entertainer. Tatiana learned a bit about singing and dancing but discovered a real talent for mimicking animal sounds from nearby farms. She eventually moved on to imitating other people's voices by practising on her father and his business friends.

World War II
Tatiana was forced to set aside her ambitions when Nazi Germany invaded the Soviet Union. She joined the Soviet Air Force as a member of the all-female 588th Night Bomber Regiment, which became better known as the Night Witches by the Germans. Taking part in a large number of raids, she became the regiment's star pilot and her face was placed on recruitment posters. Her commander, Nadia Vasney, was constantly worried about losing her to the enemy because of the potential consequences her capture and execution could have on morale. Despite her skill and fame, Tatiana became increasingly doubtful that the Soviet Union would win the war.

In the winter weather of 1942, Tatiana took part in an aerial reconnaissance mission and returned to base to report German Panzers massing to the north of Stalingrad. At the base, she encountered the Second Doctor, Jamie McCrimmon, Ben Jackson and Polly Wright. She was astonished by the fact that she and Polly looked identical. Nadia formed a plan to let the Germans capture and execute Polly so that Tatiana would appear to rise from the grave when she next attacked, thus cementing the Night Witches as real witches in the minds of the Germans as part of a propaganda coup. Tatiana, however, viewed Polly as a sign of her own salvation and made her own plans to fake her own death and escape the war.

After getting to know more about Polly's background, Tatiana abandoned her behind enemy lines before crashing her plane back at the airbase pretending to be an inexperienced pilot, and used her skills of imitation to mimic Polly's voice and English accent in order to take her place in the TARDIS. The Doctor discovered Tatiana's deception after detecting hints of her Russian dialect and then quizzed her on Polly's background; she did not know about WOTAN or computers. Despite this, the Doctor, a returning Polly and the others, understanding Tatiana's desperation, helped her stand up to Nadia, who was becoming increasingly unstable as the superior German forces approached the airbase. After Nadia was killed by Lilya Grankin, Tatiana agreed to stay in her own time and took command of the Night Witches. She led the fightback against the Germans attacking the airbase. (AUDIO: The Night Witches)

Behind the scenes

 * Anneke Wills was originally cast as Tatiana's main voice actor but this was changed when she expressed doubts about her ability to mimic a Russian accent. (BFX: The Night Witches) The role was given to Anjella Mackintosh instead, but Anneke Wills still voices the character when she is imitating Polly.
 * Because Tatiana and Polly are identical, it is not clear which one of them is featured on the cover of The Night Witches.