Doctor Who
Thirteen actors have headlined the series as the Doctor. The transition from one actor to another is written into the plot of the show with the concept of regeneration into a new incarnation, a plot device in which a Time Lord "transforms" into a new body when the current one is too badly harmed to heal normally. Each actor's portrayal is unique, but all represent stages in the life of the same character. Together, they form a single lifetime with a single narrative. The time-travelling feature of the plot means that different incarnations of the Doctor occasionally meet. The Doctor is currently portrayed by Jodie Whittaker, who took on the role after Peter Capaldi's exit in the 2017 Christmas special "Twice Upon a Time".
Alex Macqueen
Alexander Tulloch Macqueen (born 30 November 1973 in Epsom, Surrey) is an English actor. He has appeared on television, film and radio in the UK in productions such as "Holby City", "Hut 33", "Peep Show", "The Thick of It", "Keeping Mum", and "The Inbetweeners". He also voiced an incarnation of The Master in various "Doctor Who" audio plays for Big Finish, starting 2012.