After just one episode, The Bletchley Circle: San Francisco (ITV, Wednesday) seems certain to stand out from the crowd. In an age when most television dramas range from the perfectly fine to the extremely good, it already looks like a proper old-fashioned stinker.

Admittedly, one of its more obvious problems is bang up-to-date: by adhering so spinelessly to the mantra of ‘women and black people good, white men bad’, the programme not only creates an overwhelmingly dreary sense of déjà vu, it also deprives itself of any possibility of genuine dramatic tension.