Blue Bloods gaat over het leven van familie Reagan bestaande uit agenten in New York. Frank Reagan (Tom Selleck) is hoofd van de New York Police Department (NYPD). De verschillende generaties hebben grote verschillen in mening van aanpak van criminaliteit, maar één ding hebben ze gemeen, ze stoppen niet voordat gerechtigheid is geschied.

Tony Scali is a former Brooklyn cop now the Police Commissioner of a small upstate city. But for Scali, this is no desk job. He's a tough yet compassionate boss, a loving husband and father, and a hands-on law enforcer with an unorthodox style of bending the rules. From parenthood to politics, from sex crimes to murder cases, one man takes it day-to-day with offbeat humor and street- smart skill.

When a young woman's murder shows similarities to a decade-old cold case, a new police commander must break the silence permeating an Owl Mountain town.

When Karl, a young monk, comes to Bolzano after a robbery, he only reminisces about the events of the previous night. Ambitious journalist Chiara, sensing a new story, and Erich, the commissioner investigating the case, meet in the hospital room. What initially looks like a simple case turns out to be increasingly a secret network full of intrigues and criminal machinations that draws its circles into the highest social classes in South Tyrol.