Successful New York mystery author Richard 'Ricky' Castle get permission from the mayor, as a personal favor, to seek inspiration and factual documentation by tagging along with a detectives team. He soon becomes the men's friend. Castle proves to haughty Kate Beckett that his brilliant mind's ability to think like a criminal is even more invaluable in most - then his contacts and society knowledge in specific cases. Meanwhile, the greatest danger lurks in Castle's luxury apartment: his doted daughter Alexis and domineering, socialite mother Martha.