Elementary can always be counted on to provide education on the obscure to its viewers.

For example, viewers learned that politicians can be venal, greedy people on Elementary Season 6 Episode 15.

Shocker, right?

There was also a line, not at all straight, from a beheaded chicken and beheaded occult expert to rum bottling in Central America.

It did take a while (actually 45 minutes) to go from Point A to Point B and back again. But it was worth the wait.

The fun part about shows that film in New York City is having Broadway actors slum on TV for an occasional episode. The Law & Order franchise has been packed with them, and Elementary has picked up on this tradition.

Related: Elementary Season 6 Episode 14 Review: Through the Fog

This time it was Tony winner Michael Cerveris playing a helpful city councilman.

My first thought was "What's with the toupee?" Who knew that would be the plot point upon which the case of the week turned?

A headless expert on the occult, with a headless chicken and candle wax, really did scream "occult killing." We all should have paid attention to Sherlock's eye roll. After all, as he so matter-of-factly pointed out, he's been involved with 20 such murders already, then this one didn't pass his smell test.

So naturally, Sherlock let Marcus and Joan chase down the occult leads that weren't worth his time while he searched for a more realistic suspect.

Still, the investigation was going nowhere until a rum bottle with a message flew through their window.

The bottle was really a double clue. It took them to Father Vega, who educated them about the challenges faced by workers at the factory in Guatemala which produced that particular rum. He even put them on the trail of a missing union worker, who disappeared after arriving in the Big Apple.

Related: Watch Elementary Online: Season 6 Episode 14

But Valentina wasn't abducted, just hiding, as she intended to stay in America with the baby she was carrying, rather than go back and be a target for company thugs

Here's where the education came in. Apparently, labor unions help out workers in other countries get better conditions and wages. The logic is that if it's more expensive to export jobs from the US, maybe corporations think twice about leaving.

As long as there's cheap Asian labor, I don't see that concept being particularly effective. But I don't imagine unions would be doing that if it didn't work out to some degree for them.

The rum company kept track of Valentina because she had photos proving that the local militia doubled as thugs intimidating workers. She shared these photos with the occult expert, which she feared resulted in his death.

Not in the current political climate, when the powers that be are making American insular again. Few care about what's happening in one of those "shithole" countries, as long as a US company is making money off of it.

Instead, the culprit was the telltale toup'. Sighting that, the occult expert figured out it was the councilman played by Cerveris in the photo taking a bribe to vote against a tax on alcohol that would hurt that company. It also tipped off Sherlock as to what happened.

The clincher brought a whole new meaning to the phrase "chicken scratching."

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The enjoyable subplot had Sherlock and Joan taking the initiative to line up candidates to eventually replace Sherlock.

Sherlock eliminated one candidate, Detective Grimes, just because the detective and Joan were sleeping together. Based on his sexual past, didn't Sherlock have gall just bringing that up with Joan? Well, he's never lacked for gall. And she's used to it.

Sherlock did find a particularly good candidate, who correctly fit the profile I expected for Marcus's replacement: a female Latina.

She looked good on paper but was too honest for her own good. Gregson did his due diligence and ended up rejecting her.

His reasoning was sound. He already has Sherlock and Joan being too "creative," bending the rules to fit their needs in the course of an investigation.

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

Gregson had partnered Marcus with Sherlock and Joan to temper their impulses and make them color within the lines as much as possible. Marcus had evolved until the three of them became a smooth detective unit.

The captain was correct when he said it would be difficult to find another Marcus. So let's hope there's some hiccup so that it doesn't come to that.

If it ain't broke ...

To follow how Marcus, Sherlock, and Joan work together, watch Elementary online.

Should Sherlock and Joan give up their recruitment efforts? Will it come to that? How soon did you solve the case of the week? 

Comment below.

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