The climactic ending to the most recent episode of Game of Thrones, in which Arya Stark appears in the very nick of time to perform an admirably gymnastic assassination of the Night King, just as he is about to bring an end to the world of humans, has set the internet buzzing both with delighted and disgruntled fans.
Some fans referred to her as a “Mary Sue” – an idealised female character, a fiction within a fiction, who appears as a device to fulfil a plot line – on social media the day after episode three. But having survived seven series