Dies Irae, the episode title, is Latin for Days of Wrath.
Henry Ian Cusick 's character John Swift seems to be a nod to Irish-born British Author Jonathan Swift, famous for the novel Gulliver's Travel. His satirical works and political writings served as a critique of the British Empire. By the same token Cusick's character will act as an antagonist, to shock and provoke, to advance the storyline in future episodes. Cusick is half Scottish and Peruvian, in other words he has a tangential connection to the British Isles.