It was about time we got back to one of the season's most headscratching storylines.
No, it wasn't what happened to Hetty, or did the earth just swallow up Mosley whole? Not that there would have been anything wrong with that.
It was the odd behavior of Anna Kolchek over the past couple of seasons that was finally explained (somewhat) on NCIS: Los Angeles Season 10 Episode 21.
Anna's always been a love-or-hate character. Many thought that Callen frankly deserves better.
So Anna was just Miss Right Now and they both seemed cool with that.
Then, out of the blue, Anna shot an unarmed Sokolov while working for the ATF on NCIS: Los Angeles Season 9 Episode 18.
First off, good riddance.
But law enforcement frowns on shooting unarmed criminals, even if they are deserving.
And Callen's testimony on NCIS: Los Angeles Season 9 Episode 22 helped to convict Anna as well as putting their already shaky relationship in the dumper.
Anna got sentenced to seven years in prison (possibility of probation after three) on NCIS: Los Angeles Season 10 Episode 7, and then got moved to state prison then hospitalized after a fight on NCIS: Los Angeles Season 10 Episode 11.
Yeah, this string of events seemed hinky to Callen and any viewers that cared about Anna. This episode we found out it was all a long con on Anna's part.
It just took most of a season for everything to add up. I love it when a plan comes together, to steal from Hannibal on A-Team.
Of course she had to keep Callen in the dark. He's such a Boy Scout that he would ruin her plan.
He'll forgive her if she actually manages to find and rescue Callen's father.
It's times like this that having Hetty and her world of connection would be so beneficial.
I have to say that I hadn't given Anna enough credit in the past. I always thought that she was just looking for a place to belong.
I guess growing up as Arkady's daughter helped her to earn her master's in deviousness.
Obviously Anna is getting help from somebody well-placed and well-hidden in the Department of Justice. For what reason isn't at all clear yet.
So sometime after she got in trouble for the Sokolov shooting, this DoJ spook made her a deal so that she could get in tight with Kate, aka Katya.
Anna developed a well-thought-out escape plan for herself and her new BFF right under the nose of the clueless warden, in the hopes that Kate would take her back to Russia.
That plan worked only too well, to the point where Kate was willing to kill her own handler to save Anna.
Next Anna hopes to exploit Kate's relationship with security chief Volkoff.
Sounds good on paper. I suspect the execution of her plan won't be that simple.
This was a tough episode for Callen. He's blamed himself for Anna being in prison thanks to his testimony.
He shouldn't since the shooting was solely her bad decision. She let her temper get the best of her.
Callen had had a hunch right along that Anna was still on some assignment, maybe undercover. But if not for the ATF, then for who?
He also remembered Joelle (Sam wouldn't let him forget), so he had doubts and had to question whether Anna had been playing him as well, and if she might have gone back to the dark side.
Callen took the shot(s) to hinder Anna's fleeing the country. But Kate was a high-value target, as Volkoff sent in a team, on American soil, to aid in her escape.
Ultimately, his trust in Anna led Callen to let fly away, with no clear idea what she was doing. It was only later that he learned she was doing all this for him.
The best part of any Anna appearance is that Arkady is rarely far behind.
The Marshals couldn't wait to clear Arkady as a suspect and to get him out from underfoot.
Then he crashed into the OSP end of the investigation, but actually helped to crack the case, revealing Carmona's connections to Russian oligarchs and Kate's true intentions.
It was sweet how he described Anna, as it appeared that she was heading for a fiery end.
He and Rogers also became a winning odd couple, with Rogers actually driving a drunk (is there any other kind) Arkady home.
Although I'm still hoping against hope for Hetty's return to regular status, Rogers is growing on me.
He has largely come around to the team's way of doing things, although he still makes a big show of being in charge.
There are availability reasons why we aren't seeing Hetty or Ochoa or Kilbride, so I guess we need to make the best of a middling situation.
SPOILER: The search for Anna promises to continue next episode. Then it's two weeks of essentially a JAG reunion that serves as a backdoor pilot for a possible reboot to wrap up the season.
Yes, it's been a meandering season, with the Hetty, Neric, and bar storylines still unresolved. But at least we finally got the Densi wedding on NCIS Season 10 Episode 17.
To catch up before the season wraps, watch NCIS: Los Angeles online.
Who's behind Anna's mission?
Will she come back?
What about Callen's father?
Dale McGarrigle is a staff writer for TV Fanatic. Follow him on Twitter.