The world of jealousy is fraught with danger and drama at the best of times. 

This Criminal episode took an old bit of wisdom ("Can you truly trust someone with whom you've cheated?") several steps past dangerous and into fatal territory.

Once again the viewers went on a ride with the team as they struggled to figure out the puzzling behavior of the Unsub, who at first kidnapped married couples and forced them to cut and then kill each other. He later left them in the trunks of their cars. 

But then his methodology changed and he only abducted married women and killed them. I'm not sure the episode explained why this took place, except that perhaps he found a more satisfying approach in substituting himself for the husbands. 

The BAU eventually learned that their supposed victim "#6" - Phillip Connor - was actually the Unsub.

They learned some important details about him from his mother:

• He had an affair with a woman to whom he got engaged, while she was still married to another man.
• His logic couldn't ignore the fact that if she cheated on her husband, she might cheat on him too.  This soured him on relationships in general.
• He was a cutter, and he knew he was mentally ill. 
• His fiance left him because of it.
• He enjoyed his illness because he reveled in the attention it brought him.

He was pretty much a classic narcissist, who in this case was also a sadist. I'm beginning to think that "narcissist" is the common bond between nearly all of the BAU's Unsubs.  Sort of a "me me me and if it's not about me then I will get all stabby with you" deal. So far, it's a fair guess that the mysterious Replicator is singing a similar tune. We'll have to wait until next week to be sure, though.

At any rate, the BAU was able to track the Unsub down and trick him into giving up his latest victim by having his ex-fiance pretend to want to talk with him. After he gave up his victim, and was in custody, she couldn't get away from him fast enough.

There were two positive BAU character developments in this episode that are worthy of note: First, Reid seems to be back to his old self. No doubt he still thinks about Maeve a lot (as evidenced by his heart to heart advice to Blake), but there were a few gems he threw out in this episode (some of which are contained in our Criminal Minds quotes):

Rossi: So, we know the Unsub uses the victims' own cars as his dump site.
Reid: Technically it's not a dump site. It's transportation disposal modality. | permalink

The other cool thing about this episode was that we got to learn more about Alex Blake, who has been a bit of a mystery for the whole season.  We knew she was extremely intelligent, perhaps an intellectual peer of Reid. 

We knew there was some baggage between her and the BAU director Erin Strauss, the latter of whom earlier sabotaged Blake's reputation within the FBI (though we don't know the details of that event). We've seen Blake as mostly an analytical, except when it came to helping Reid with his relationship with Maeve.  What we haven't seen until now was her home life. I had no idea until now that she was married.

The subplot that portrayed her as one half of a very loving couple also served to point out the thing that drives her: she is keen on rebuilding her reputation within the FBI - which is more important even than just working with the BAU itself. 

Her husband James' desire for them to work together was understandable, especially given his long trips overseas to work with Doctors Without Borders. He thought he was doing a good thing by making his employment with Harvard conditional on them accepting Blake as a professor of linguistics. When Reid offered his advice that she should make her decision on the fact that such loving relationships are rare, I truly wondered if she would quit the BAU and go to Harvard. 

It was not to be. Blake is a driven woman and her job and purpose at the BAU was too important for her to give up. I understand that, too. Some things define us, and putting them aside means negating in some way who we are. 

That said, I really want to know more about what Strauss did to her. Hopefully the writers will fill in the blanks for us soon.

What did you think of tonight's episode? What are your thoughts on Blake, the peek into her married life and the motivation for her career at the BAU? Were you convinced about the plausibility of the case itself? Were you surprised, as I was, that it's possible to hack into cars the way Morgan described by using a $20 gadget you can buy anywhere? 

Douglas Wolfe was a staff writer for TV Fanatic. He retired in 2016. Follow him on Twitter

.