No single source is cited as inspiration for the screenplay by William Nicholson and Simon Beaufoy (who know a thing or two about wilderness survival stories, having co-written «Unbroken» and «127 Hours,» respectively), though the press materials mention books written by two American survivors of the climb: Jon Krakauer's
bestseller «
Into Thin Air» and Beck Weathers» «Left for Dead: My Journey Home From Everest.»