It took me a 3 screenings, but I figured out what's going on her; at least I think I did. See where your own intepretation takes you.
Idris Elba has been on a music video directing kick lately, after having recently directed one for one of his own tracks, while shooting his Mandela film in South Africa. I'd say his warming up for his feature film directorial debut, won't you?
Watch the Mumford & Sons video below, for a track titled Lover of the Light (the title is obviously a clue):