Doctor Who: 9 Things You Didn't Realise About Series 1 Of NuWho

5. Doctor Sato

A spaceship containing a space pig crash landed in the Thames during the first NuWho two-parter, Aliens of London and World War Three, and, luckily for the human race, there was a more than capable familiar face on the case. How's that for a rhyme!? As pictured above, Naoki Mori guest starred in the story as Dr Sato and at that point viewers had no reason to suspect that she would go on to become a significant character in the world of Doctor Who's extended universe of Torchwood. The actress stepped back into the shoes of the character for a leading role in the show's spin off in 2006 where her first name was revealed as Toshiko and it later transpired that she had been covering the space pig incident for the team's actual doctor, Owen Harper, who had been too hungover to investigate it himself. Toshiko was a formidable force on the Torchwood team and it was genuinely heartbreaking to have to say goodbye to her at the end of its second series. At least she got to meet the Doctor, though, as she managed to leave her mark on the franchise's parent show despite the fact she was tragically killed off before the official crossover took place in 2008. Toshiko Sato, you are sorely missed.