s ▁nin th ▁novel , ▁published ▁between ▁A ton ement ▁and ▁On ▁Ch es il ▁Beach , ▁two ▁nov els ▁of ▁historical ▁fiction . ▁Mc E wan ▁has ▁discussed ▁that ▁he ▁pre fers ▁to ▁alternate ▁between ▁writing ▁about ▁the ▁past ▁and ▁the ▁present . ▁ ▁While ▁research ing ▁the ▁book , ▁Mc E wan ▁spent ▁two ▁years ▁work - shadow ing ▁Neil ▁K itchen , ▁a ▁neu ros ur geon ▁at ▁The ▁National ▁Hospital ▁for ▁Ne uro log y ▁and ▁Neu ros urg ery ▁in ▁Queen ▁Square , ▁London . ▁K itchen ▁test ified ▁that ▁Mc E wan ▁did ▁not ▁fl inch ▁in ▁the ▁theatre , ▁a ▁common ▁first ▁reaction ▁to ▁surg ery ; ▁" He ▁sat ▁in ▁the ▁corner , ▁with ▁his ▁not ebook ▁and ▁p enc il ". ▁He ▁also ▁had ▁several ▁medical ▁do ctors ▁and ▁sur ge ons ▁review ▁the ▁book ▁for ▁accuracy , ▁though ▁few ▁corre ctions ▁were ▁required ▁to ▁the ▁surg ical ▁description . ▁ ▁Saturday ▁was ▁also ▁proof - read ▁by ▁Mc E wan ' s ▁long standing ▁circle ▁of ▁friends ▁who ▁review ▁his ▁manuscript s , ▁Tim othy ▁G art on ▁Ash , ▁Craig ▁Ra ine , ▁and ▁Gal en ▁St raw son . ▁ ▁There ▁are ▁elements ▁of ▁aut obi ography ▁in ▁Saturday : ▁the ▁protagon ist ▁lives ▁in ▁Fitz roy ▁Square , ▁the ▁same ▁square ▁in ▁London ▁that ▁Mc E wan ▁does ▁and ▁is ▁phys ically ▁active ▁in ▁middle ▁age . ▁Christopher ▁H itch ens , ▁a ▁friend ▁of ▁Mc E wan ' s