Castle first aired on ABC in 2009, starring Nathan Fillion as author Richard Castle. After killing off the main character of his extremely popular book series, he tells his daughter that he wishes something in his life could be different. Immediately he is approached by Detective Kate Beckett of the NYPD, who needs to ask him questions about a murder that mirrored his books perfectly.

So the saga began. Castle helped Beckett (Stana Katic) solve the mystery, and then pulled some strings to shadow her on the job so he could use her as inspiration for his next book. Beckett can't think of anything worse than a flirty man-child following her around, but he worms his way into her heart nonetheless. Over eight seasons, we saw Beckett's character evolve from a no-nonsense detective with emotional walls thicker than steel, to someone who was able to let people in. Castle and Beckett bring out the best in each other. She never lets him get away with anything, and he reminds her that even on the worst days, there is a possibility for joy. Then, in mid-April, it was announced that Stana Katic and Tamala Jones (who played Lanie, Beckett's best friend and the medical examiner) had been fired from the show. Fans were in an uproar.

The show's plot lines had been going off the rails for some time; Castle disappeared right before their wedding, and the explanations for why he did and why he couldn't remember were getting stranger and stranger. He was also no longer able to shadow Beckett, so he became a private investigator himself. However, the show's strongest point has always been Beckett and Castle working together, and without that the show felt empty. With the news of the permanent loss of Beckett and Lanie (which many knew would probably entail Beckett's death in the season finale), fans were clamoring for the show to end before it could get worse. For this reason (and many others, fans are sure), ABC announced that season eight would be the final season of Castle.

It's always sad when your favorite show ends. Castle has been an amazingly wild ride. The cast is incredible and the characters unforgettable, from the two police captains the twelfth precinct has seen, to Beckett's right hand men, Ryan and Esposito. Castle's mother, Martha, and daughter, Alexis, have also helped in solving many of their cases, and never fail to ground Castle and support Beckett. They're all a family, and without Lanie or Beckett, the show would lose that. The entire team helped to solve Beckett's mother's murder and to uncover the conspiracy behind it, a feat which lasted for a better part of the show's run. However, it was never overwhelming or dragged too far, unlike the "disappearing Castle" arc, which had no clear answer. In the final seasons, the team delved deeper into a bigger conspiracy that pulled together all the greatest mysteries of the show and narrowed it down to one person and organization. The finale saw a resolution to this arc, which fans were happy about.

It was clear that the finale was meant to be a cliffhanger if the show had continued. Beckett and Castle returned to their apartment, thinking it was over, but at the last second, an enemy emerged and shot them both. Beckett managed to shoot him as well before she collapsed. She crawled over to Castle and they laid on the floor in almost the exact position as the season's promotional ad. The camera panned across the apartment, and we heard their final words to each other from the first episode over again. It's easy to assume that the there was a season nine, it would pick up in the same place, most likely with fans finding out that Beckett had died from her injuries and Castle had survived. Instead, fans were treated to a brief glimpse into Castle and Beckett's life seven years later. The loft is filled with children's toys, and the couple is happily sitting down to breakfast with their three children. Despite the deus ex machina style of the ending, it was the one fans deserved and it was the right choice to make. Castle will be missed, but fans couldn't have asked for a happier or more bittersweet ending.