Nothing is ever simple for Callen, is it?

Grisha's mysterious history popped up once again to make his life difficult on NCIS: Los Angeles Season 14 Episode 16.

And, not at all surprisingly, Hetty may or may not have been part of this case of the week.

Even from thousands of miles away, Hetty still can pull strings. That was likely the case here, but who can confidently say?

This episode ticked off a couple of items from the ongoing-storyline lists. Hetty was actually brought up repeatedly, and the Drona Project is the central storyline.

So the series wasn't simply treading water for a change, which is a nice touch in a final season.

Even better, this was an episode featuring Shyla, who has managed to become an integral, recurring character over the past couple of seasons.

Shyla has managed to replace Nell and Eric, someone in Ops who can run an investigation flawlessly, especially on those episodes when Kilbride isn't totally checked in, like this one.

The admiral could be cut some slack as he was planning to fly to San Francisco for that long-overdue, heart-to-heart conversation with his addict son, Alexander.

Shyla knew the situation as soon as she had scoped his packed suitcase. She also realized how important it was that Kilbride take the step that he had been putting off for so long.

That was why she ignored his order to cancel the flight in the heat of the investigation. Shyla is the only one who can get away with forcing Kilbride to do something that he doesn't want to do.

Shyla also knows when she doesn't understand something, which is rare. That was why she summoned Sam and Callen when she couldn't understand the cryptic top-secret message with just two driver's licenses and a six-digit number.

When she revealed that the message from sent from a skiff near Hetty's last-known location, that just added to the mystery. Coincidence? When Hetty is nearby, hardly ever.

Kilbride pieced together that the two murdered men were Drona Project subjects. Callen recognized the third number as belonging to Leah Novak, the subject who had rejected Callen's help on NCIS: Los Angeles Season 13 Episode 7.

It was hard to blame Leah for being skeptical about Callen's warning. After all, she had parted from him after discovering that he had lied to her about who he was.

But, like Jenkins, Leah had received a warning text. She just hadn't run fast enough. But she did give Callen a clue, the number 14, although he didn't understand what that meant until it was just a little too late.

Jenkins' recovered phone led Callen to Beltran, Drona Project's subject Number 14.

Only as Sam and his team and Callen independently determined, all was not as it initially seemed. The three shot agents were working for Pembrook while Beltran was hunting him.

So what Callen ended up learning from this whole adventure was that the survivors of the Drona Project had quite different motivations.

Callen wants to learn more about his involvement with Drona and bring Pembrook to some kind of justice.

Others are either working for Pembrook or want him dead. So Callen will end up facing more obstacles than he had initially foreseen.

A frustrated Callen admitted to Sam that he had hoped to turn the page on this part of his life. He also was hoping that Hetty would soon return. But he wasn't willing to keep pushing back his wedding for that to happen.

Seriously, does anyone believe that Callen and Anna's wedding will occur without Hetty?

Callen did manage to take care of one wedding-related activity this week. He lined up his best man.

Not that Sam made that particularly easy for him. But that was Callen's fault.

He just threw down a picture of the formalwear the best man would wear in front of Sam. He thought it was a fait accompli.

But Sam insisted on being courted. Once Callen got around to officially asking him, of course, Sam accepted. He had so much that he wanted to warn Anna about, like she didn't already know better.

And, out of left field, Rountree is in a relationship. His ex, FBI Agent Summer Morehurst, was introduced on NCIS: Los Angeles Season 14 Episode 8. 

The way things were left, Rountree would attempt to win her back. Apparently that worked, as they were back to being a couple a scant eight episodes later. I guess when the end is coming, there's little time to slow-walk developments in a relationship.

At this rate, Fatima and his boyfriend Akhil will have eloped to get married in Vegas between episodes. After all, that would be appropriate for a relationship that has been developed mainly offscreen. And what better place for a Muslim couple to wed than Sin City?

Also, does Devon's renewed relationship with Summer mean that he and his partner Fatima won't be getting together, as often has been speculated? That's fine. There's nothing wrong with a platonic relationship between partners.

To revisit the Drona Project, watch NCIS: Los Angeles online.

What did you think of the developments in the Drona storyline?

Was Hetty involved as it appeared?

What's your opinion of Rountree and Summer getting back together?

Comment below.

Dale McGarrigle is a staff writer for TV Fanatic. Follow him on X.