It’sthedeepestpartofwinter,theexactmidpoint,ChristmasEve–halfwayoutofthedark.AmyandRoryaretrappedonastrickenspacelinerthat’splummetingthroughbanksofthickicyfogtothesurfaceoftheplanetbelow.Onlyonemanhasthepowertosavethem;onlyonemanisinpossessionofamachinethatcanclearthefogandletthemlandsafely.ThatmanisKazr...