The team face unique challenges when they have to investigate a murder at a sci-fi convention on Castle. "The Final Frontier" is the sixth episode of the show's fifth season.
Lanie, Castle, and Ryan are swapping theories but at this point they have no idea that their latest murder will lead them to the Captain's estranged sister.
Ryan, Castle, and Beckett investigate when a dead woman is found in a parking garage on Castle. "A Murder Is Forever" is the eighth of the show's sixth season.