Sara Powell

In the middle of Crimean War (the year 1855) the Doctor and her companions cross paths with Mary Seacole, considered by some to be the first nurse practitioner, an istoric figure that helps the wounded from both sides in conflict. Historical speaking, in that war the British fought the Russian in the peninsula because the Otoman empire was collapsing. Mary Seacole was supposed to be there and then, but the several space ships full with Sontaran warriors were new and out of place. Especially that they were already ruling a big territory (as Russia and China together - and I think that's not a mistake, considering the tension the two countries have been provoking lately).