Director Douglas Mackinnon, pictured in 2007.
Douglas Mackinnon is one of the series’ most prolific directors, having put the last three Doctors through their paces across eight different episodes between 2008 and Christmas 2015.
Of those eight episodes, half feature some element of an invasion plot – 2008’s The Sontaran Stratagem/The Poison Sky, The Power of Three from 2012, and the more recent Flatline, which formed part of Peter Capaldi’s début series as the Doctor in 2014. Three adventures, three invasions, yet all wildly different.