When an ER physician is gunned down in the street, Castle and Beckett soon discover that the victim was a mob doctor to a Mafia family run by an old friend of Castle's. Also, against this backdrop of Christmas, Esposito and Lanie reach a defining moment in their relationship.
Keywords: criminal-consultant , criminal-investigation , female-detective , homicide-detective , new-york-city , novelist , police , police-procedural , writer , watch-series-online