Ugh Castle and Beckett got to see Hamilton on Broadway? How did they snag those tickets? So jealous. But anyway, this was pretty much your standard-issue Castle episode. Nothing to write home about, but nothing bad either. Let's dive in.
Jewel Staite should, by all rights, go in the "pros" section, but I have to admit that seeing Fillion's Firefly co-star in this episode made the reveal of the murderer super obvious. It was one of those obnoxious "twist" endings where after dealing with fierce mob bosses and drug dealers and all this stuff, the murderer was actually the woman we saw for just a minute at the beginning of the episode. We never talk to her or build up the reveal in any way, and yet I still knew she was the killer because you don't bring Jewel Staite in to play such a small part unless she gets to have the confession speech at the end. It was just disappointing to waste her on such a nothing part without a lot of meat to it. She and Nathan Fillion hardly interacted at all!
Another point along the same line - Martha showed up in the secret hotel room of the murder victim, and it turns out she was giving him acting lessons. The only problem is that from that point on, she had almost nothing to do in the story. If you want to do something focused on Martha, then great! But don't dangle her character in front of us for just a second and then not have it lead to anything!