"Law & Murder" is a standard Castle episode--a case with several twists, a strong sense of justice, teamwork, and an Alexis dilemma which ends with her looking like a saint. There's nothing that really sets the episode apart from the pack, but a couple things that stuck out in my mind--Montgomery's involvement in the case and Alexis's line about her friend situation being complicated, a possible precursor to a more substantial plot.
Score: 8.7/10