Since the first letter in the show's title stands for "Naval," it's only appropriate that this episode was filled with red herrings.

NCIS: Los Angeles Season 11 Episode 4 seemed like an effort to clean up a barely dangling storyline.

Callen and Sam found themselves back on board the USS Allegiance, under the guise of accompanying Ehsan Navid, last seen on NCIS: Los Angeles Season 5 Episode 14 and expected never to be seen again.

But no, Ehsan has repaid Callen and Sam's earlier kindness by becoming an NCIS agent. He was now appointed as the agent afloat for the Allegiance, replacing Brian Lee, killed on NCIS: Los Angeles Season 10 Episode 23.

Callen and Sam came along to help Ehsan with the transition to his new post.

Of course, nothing is ever that simple.

Harmon Rabb of JAG fame, the Allegiance's X-O, wasn't around because, well, that ship has sailed.

Related: NCIS: Los Angeles Season 11 Episode 3 Review: Hail Mary

Nah, not really. He was testifying to a Congressional panel, likely because he drew the short straw, about the ISIS infiltration of the ship somewhat resolved on NCIS: Los Angeles Season 11 Episode 1.

(Where's that JAG reboot? Still in dry dock, I'd guess.)

It's been a few episodes without a jihadist threat. And the last episode on the Allegiance left the question of further ISIS collaborators hanging.

So why stretch too hard for an original idea? Why not just go back there already? I mean, the set was available.

I know. It made sense from a production standpoint. Yada, yadda.

At least the narrative took a hard turn back to Los Angeles.

At the heart of the episode was a junior officer from the Allegiance who became infected with Ebola.

This led quite handily to a two-front episode, with Sam, Callen, and Ehsan on the quarantined Allegiance while Kensi and Deeks and Nell and Fatima in Ops attempted to locate the officer's killers before more people become infected.

It was good to see Fatima back in Ops. Hopefully, this will remain the pattern until Eric returns, with other recurring Ops characters helping out Nell. She shouldn't have to shoulder the burden all by herself, what with her running back and forth to San Francisco.

Plus it came in handy having someone who could speak Farsi when a recalcitrant Iranian source needed a tongue-lashing.

Yeah, it would be good to have Fatima there on a more regular basis so the three of them could rotate and get in some field time.

Of course, none of that happens until Eric returns after a couple of more episodes. Hopefully, his return will be heralded when that happens, unlike on NCIS: Los Angeles Season 11 Episode 3 (an episode that was in the can already).

Anyway, it soon becomes apparent that a public health emergency could be in the offing in both locations, hence the ship's quarantine.

The CDC couldn't just shut down Los Angeles that easily nor even mention Ebola above a whisper.

Instead, finding the extremists who had hoped to use the infected officer as a weapon became the priority because with her dead, their plot took a real detour.

Related: Watch NCIS: Los Angeles Online: Season 11 Episode 3

Credit needs to go to the officer who foiled their plan up until her dying breath.

Yeah, it was stupid of the kidnapper "Jenny" to use the officer's credit card to buy a bus ticket out of town.

That made her an easy target for Deeks and Kensi, with crazy Deeks frightening her right into Kensi's taser.

"Jenny" was too much of a zealot to give away her partner, but she did inadvertently reveal the target so that Deeks and Kensi could stop her partner before he hurt anybody.

It was obvious pretty early that something was bothering Kensi.

Deeks determined it wasn't something he had done when gungho Kensi refused to follow the blood trail into the warehouse without hazmat suits.

She did fess up to being late and maybe pregnant, which was why she was uncharacteristically not taking any chances.

One clear thing was that a pregnant Kensi would have to relearn how to do her job.

Deeks did the right thing by not piling on her since he knew that they disagreed about having children.

It was a false alarm, but it did reveal how insecure Deeks is. He knows he's lucky to be with Kensi, and he keeps expecting that not to last. Maybe she reassured him but probably not.

Things weren't adding up aboard the Allegiance.

Lamb, who had given Ehsan so much attitude, wasn't the sympathizer they had feared but rather someone who had mistakenly befriended one of the ISIS infiltrators.

It seemed like he finally got past blaming all Muslims by the end.

While a handful of people manifested symptoms that could be Ebola, the L.A. investigators were able to confirm that the officer got infected after leaving the ship.

Having Ebola get onto the ship through an infected officer made sense. People contracting psychosomatic conditions was less believable and a bit disappointing.

Related: Get CBS All Access via Amazon Channels for Hit Shows, Exclusive Originals & Live TV!

That being said, the Ebola threat was real enough. Having Col. Kaufman explain the effects of the disease in the Congo was heartbreaking.

It was sad that Kaufman did everything right so that she could see her new granddaughter, but because she put duty first, she was still going to have to wait weeks to see her.

It also appeared that Kensi might be softening on the idea of having children as she looked at photos of Kaufman's granddaughter.

To follow the Allegiance storyline, watch NCIS: Los Angeles online

Were you surprised the Allegiance wasn't infected?

Do you enjoy seeing Fatima again?

Did you get informed about Ebola?

Comment below.

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