*Review contains spoilers, so read at your own risk!*
It's been such a long time since we had an action filled, drama filled episode, that it was so nice for us to finally have one. Not that I mind the fun episodes. It's just nice to have one of these every once in a while to change it up. And speaking of changing it up, they put someone else besides Kate or Castle (not that I mind that either) in danger.
Espo is the one who gets to have the spotlight. Haven't seen him get to shine in a long time and it was refreshing. Their new case leads them to one interesting new suspect that opens up a completely different case then they were expecting. Espo and Ryan just so happen to randomly see their suspect and Espo goes to talk to him. Little does he know, that the guy is actually planning on doing something big. The guy had to change up his plans, though, when Espo came and the suspect ended up taking the subway train captive instead of the place that he wanted to do.
Poor Ryan has to kind of sit back, well, not really, but he can't stay at the scene and wait to find out what happens. Which probably is a good thing since the situation was just goes from bad to worse. But Kate needs him to find out more about this guy that is keeping this train hostage and figure out why he would do something like that.
Now we learn the truth. The guy did this all because he wants to get his girlfriend out of jail. However, he wasn't the one that was in charge. He had instructions on exactly what to do. Why would someone like that have instructions? Turns out, this ended up being a whole distraction to what the person really wanted to happen.
Paul, the dead guy at the beginning, was investigating the place he worked at after they had ordered a bunch of flu vaccines for a virus that hadn't had an outbreak. But if it did, it would be deadly. The company just wanted to do a pandemic and then make millions by having everybody come to them for the vaccine.
So yep, in the end, Espo and the people on the train get out fine and get vaccinated. While all of this is going on, Espo is having second thoughts on his relationship with Lanie, which I was disappointed to hear. However, I hope that after this near death experience, Espo will think more about the relationship, which the cop lady politely pointed out that clearly Lanie means more to him then he realizes.