Castle the TV series was not only known for the explosive chemistry of its two leads, Rick Castle (Nathan Fillion) and Detective Kate Beckett (Stana Katic), but also for the amazing cases that the duo solved. The cases in the series range from everyday crimes of passion to conspiracies that go all the way to the top. Regardless of the glamor, the detective, and Castle, take every case seriously, and work tirelessly to bring the criminals to justice.