After 4 years of cooperation, dozens of cases and a near-death experience, Kate Beckett (Stana Katic) finally confirmed her feelings with best-selling author Richard Castle (Nathan Fillion). Although they still have a lot of things to get along with each other, and even have little secrets that have never been confessed to each other. But they have to face the reality that an unwritten rule of the New York Police Department does not allow colleagues to fall in love. How to hide the sweetness of the two is more difficult in the later plot. Richard takes Kate to his Hampshire villa on the weekend, thinking about the world of two people, but the murder case entangles them like a shadow... Can this pair handle each other's feelings as tacitly as they handle work?