Don’t switch off before the very end! The parallels with John Wyndham’s “Day of the Triffids” are many, from the hospitalised central character surviving in the first instance because he’s unconscious in a bed, to the colony of survivors aiming to repopulate the world. In this story, it’s not an accidental escape of genetically engineered carnivorous plants (cultivated for oil, was it?) on their gruesome quest to feed and multiply, but a “rage” virus, developed for whatever wicked purpose, possibly as a wmd. I can’t remember, but it’s not too important, because it’s the survival story that really matters in this, as well as in Wyndham’s novel. We meet Selena (Naomie Harris) when she has already acquired the necessary survival instinct to kill or be killed, and we watch as the erstwhile bike courier Jim (Cillian Murphy) gets to that stage, possibly a bit beyond, since his bond with Selena and Hannah (Megan Burns) motivates him to protect them. He becomes this small wraith-like figure who manages to outwit the burly soldiers, even appearing to recruit an already rage-infected one who’s been chained up until freed by him. I loved the optimistic ending, with Selena and Jim together, Hannah as their little sister – just like Bill, Josella and Susan in the Triffids – but then as the end titles scrolled away and I reached for the kettle, up comes “what if…?” Uh-oh, just when you thought…. Brilliant, Danny Boyle, just brilliant.