A harmless, self-contained episode can be a wonderful change of pace.

There were no grand conspiracies or involved storylines on NCIS: Los Angeles Season 9 Episode 4.

There was just a truckload of stolen guns and a chance for some undercover work.

It wasn't even good undercover work, mind you. Mosley went as herself, and Sam and Callen got to be her security detail to be seen but not heard. That kind of speaks to their current relationship, doesn't it?

Even Harley got a better undercover role, matching up guests with their firearms. Yet she did more than holding a tablet this time. She impressed Sam and Callen by lifting a tablet with the information they needed, then she shot a bad guy sneaking up on Callen.

OK, she's growing on me. She blends well with Nell and Eric in Ops, and she readily admits that she doesn't know what Mosley is thinking most times.

Whether she's actually needed is a whole other question. It seems that Anna is being phased out now that she probably has a job with ATF, so there's some room for another recurring character.

Speaking of recurring characters, this time it was Byron Brown, whose Kulinda security firm Sam infiltrated on NCIS: Los Angeles Season 8 Episode 12.

The problem is that Byron was somewhere involved with the theft of $1 million worth of military weapons. A video Eric found showed Byron accepting the truck with the guns from this guy who looked like he should be saying, "Do you want fries with that?" In other words, he wasn't a particularly talented criminal.

For some reason, for the first two-thirds of the show, Sam and Callen were more concerned with the question "What is Byron doing?," instead of the more important "Why is he doing this?

They fell back on the time-tested TV trope of "his family is being held hostage." It took about 90 seconds for Kensi to take out the gunman straight out of Militia Man Monthly and free Byron's family.

At least they didn't go with gambling debt or drug problem. It's harder to rehabilitate a character from those conditions.

It was a clever set-up, with the heist mainly to get ahold the gun truck. Since the weapons weren't the prize, something else must be happening instead, such as an assassination.

This was also Mosley's coming-out party.

How'd she do? Well, nice dress. Also, she had some really expensive guns and showed that she knew how to use them. She wasn't much at schmoozing, which is always the key to good undercover work.

I guess her role was getting them in the door, as that was the bulk of her contributions. Sam and Callen did all the gathering of clues, and pretty much did things as they always have, without stopping to consult with Mosley on each move. End result, baby!

The producers need to start doling out more information on Mosley quickly, before viewers turn her appearances into a drinking game. ("Frowns at Deeks. Drink! Acts exasperated by Callen. Drink!")

As soon as I heard Bradford say he was getting the company out of weapons sales, I knew he was in trouble. Fortunately, that problem was solved with a tackle by Callen, a near-impossible shot by Sam, and a shot in the back by Harley.

And, of course, the haughty rich bitch was behind it all. (I loved Rebecca Wisocky on Devious Maids, and this was largely the same character.) How dare he mess with her cash flow?

Deeks and Kensi did what they do best while chasing down the two-bit thief who stole the guns: comic relief.

Shortly after he recently talked about staying home as a Mr. Mom, Deeks has fallen in love ... with a sports car. He mainly took selfies behind the wheel of the Porsche he borrowed from the unit motor pool while Kensi's Audi was being serviced. He let his goofy self loose.

To make matters worse, the car is Mosley's, and Deeks scratched it.

Meanwhile, Kensi took care of business tackling a suspect and gunning down a henchman all while still finding time to roll her eyes at Deeks.

I don't give much love to Eric, but I did enjoy his Scotty reference even if no one on his team (except maybe Nell) got it. Yes, Eric, you are so alone.

Hetty was nowhere to be seen again, except in the recap, although Eric did locate her abandoned boat in Kauai. I fear her Vietnam odyssey is going to be a long, drawn-out storyline with a scene about every third week or so. I'd love to be proven wrong on this front.

SPOILER ALERT: The parade of recurring characters continues on NCIS: Los Angeles Season 9 Episode 5, when Arkady returns to help out with the investigation of a murder of an investment banker tied to a Russian oligarch.