The fifth season kicks off with Watson still living in the brownstone, so I guess she decided not to stay in Moreland's safe house or whatever it was. Am I even remembering right? It probably doesn't matter. Safe to say we start with a kind of "reset" in which normal, such as it is for these characters, has been re-established.
Plot? Oh, something about a bomber. Holmes and Watson zero in on the culprit fairly quickly, and from there it's a matter of proving it. A lot of blind alleys, but of course Holmes ends up being right in the end. No, I don't consider that a spoiler. I think it would have been more interesting if he hadn't been though.
The "real" story in this episode—the emotional underpinning anyway—is about how Watson may or may not (a) be getting bored with being a detective, and/or (b) miss helping people the way she did as a doctor or sober companion. Holmes naturally points out that they help people, too, by finding the bad guys and putting them away, but there is, of course, a distinction. It's one thing to actively help people and witness them getting better. It's another to avenge those who have been victimized. Group A has the sense of being there in the nick of time. Group B is more like cleaning up the mess when it's too late to really save anyone.
Watson isn't getting bored, but she does miss being Group A rather than Group B. Lucky for her, this episode introduces someone she once performed surgery on—a man who recently got out of jail and is looking to get back on his feet. Through Holmes' persuasion, Watson goes to help the guy in Group A fashion. Similar to being a sober companion, maybe she can keep ex-criminals from backsliding?
In truth, it wasn't an episode that wowed me, and I hope the season doesn't attempt to string out this Watson angst. The character arc is natural enough, but somewhat somnolent. Angsty Watson is less entertaining than angsty Holmes, not because of the angst but because of the way the other character responds. Holmes isn't a natural nurturer; Watson is. Maybe if we saw Holmes being more uncomfortable in the role of nurturer when Watson needs that, it would be more interesting. As it is, it just kind of happens with no real tension. However, when Watson is called upon to nurture Holmes in some way, Holmes' spiky nature does add tension and often comic relief. It hearkens back to the initial conceit of the series, in which Watson was a somewhat unwelcome addition to Holmes' life. That conceit worked and still does when tapped.
Alas, ratings for Elementary are slumping. The Sunday night time slot isn't great, and there are times the show seems to have run out of ideas, if not for crimes of the week then for the characters themselves. It could also be that we're seeing the downward arc of the recent spike in Sherlock Holmes' popularity in general; these things come and go in cycles, after all. Like a Ferris wheel—try to enjoy the way down as much as the way up, and please wait until the ride comes to a complete stop before disembarking.