This was a perfect example of a breather episode.

Elementary Season 7 Episode 7 was self-contained so if a viewer missed it because he or she was out enjoying the Fourth of July, they really lost no ground on ongoing storylines.

You know, like procedurals used to do when viewers couldn't stream episodes they missed. That way, no one was lost the next week and could jump on any time they wanted, and didn't have to depend on reruns to fill in any gaps.

Remember when reruns were reruns before they started being puffed up by networks calling them encores, like they were some special treat viewers just couldn't miss.

Before the powers that be determined that viewers would rather see something new and reruns largely went away.

Unless, of course, they were from a non-serial procedural, because viewers can't be trusted to figure out things on their own.

Ah, the good old days!

Related: Elementary Season 7 Episode 6 Review: Command: Delete

But I digress.

The case of the week certainly started with an ideal victim: A robber who targeted other criminals. That created a large suspect pool right off the bat

Then he died supposedly from handling $200,000 in Fentanyl-coated bills. Well, at least he died happily.

But Sherlock, Joan, and Dr. Hawes quickly shot down that possibility, citing recent medical literature. 

The robber's girlfriend insisted there was no way that he had ingested the Fentanyl. He never took drugs, then since his brother died from an overdose. He actually went out of his way to target drug dealers.

Sherlock returned to the scene of the crime and discovered cat hair all over Dineen's apartment, only found no supplies which a cat owner would need.

That led him to the murder weapon, an inhaler laced with Fentanyl used by Dineen when his  allergies were aggravated by the cat hair.

That was when the possiblities started getting loopy.

The aerosol Fentanyl was a weapon secretly used by the Russian government. So the Russians must have wanted this penny-ante crook dead..

This was a great opportunity for Sherlock to resurrect his Russian contact, Olga Berezhnaya, a former spy last seen on Elementary Season 4 Episode 9 who was now working as a first-grade teacher.

Olga had never heard of Dineen but Sherlock pressured her to make a few calls anyway.

Related: Watch Elementary Online: Season 7 Episode 6

This continued this season's trend of reviving memorable past characters for one more time in the spotlight, even if he or she was only on once previously. This is to be encouraged since Elementary has enjoyed many such characters through seven seasons.

Olga invited Sherlock to lunch and unveiled that one of the scientists who had created the weaponized but never unveiled Fentanyl lived in an apartment across the street. But then the Russians blew him up before Sherlock could question him.

Another dead end.

Next, the blood on Dineen's gun led to an unexpected second victim, Cecil Troy, a textile restorer with whom Dineen had grown up. Troy was the one who had pointed him to the stash house.

The solution was actually bulletin-board material which Joan spotted while being kept waiting at the local DEA office.

Troy and Aubrey Kensit, his business partner, had received a contract from the DEA to launder drug-coated money to keep its agents safe. But, as mentioned earlier, medical research put little stock in a person receiving enough of a dose from such money to endanger them.

So they set up Dineen to prove the danger, putting drug-laced money in his posession then tampering with his inhaler so that he inhaled a lethal dose of Fentanyl. 

While Troy met his end via Dineen, Aubrey set up Dineen's apartment to finish him off. But her own cat was likely to end up testifying against her.

Once again, Elementary managed to be timely and mind-bending.

Related: 17 'Ships That Will Never Sail, but Should

I felt badly for Captain Dwyer.

He seemed destined to go out as a short-time substitute curmudgeon. But instead, he ended up being an object lesson.

It seemed like Dwyer and Gregson were close, listening to Dwyer wax poetic about their old times.

But then one of Gregson's top detectives, Bree Novacek, tells him she's leaving for the private sector, and his mind leaped immediately to Dwyer, who had a history of being inappropriate with women.

Two questions: Why hadn't Marcus heard anything about Dwyer through departmental scuttlebutt? If Bree was one of Gregson's best detectives, why have we never seen her before?

He asked for Joan's opinion and she basically hadn't seen anything, which was unusual for an experienced investigator.

Gregson confronted Dwyer, which went nowhere.

Then he tried to pin down Bree, who gave him a non-denial denial. In the end, Bree came forward, which I guess was the point of this storyline.

It was a way to illustrate how police departments can be old-boy clubs. It just didn't happen very organically.

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

As for the group of vigilantes Sherlock was pursuing, that was largely glossed over, with him telling Marcus that their investigation was going nowhere, to protect him. 

With only 13 episodes in this final season, I can't imagine there will be too many self-contained episodes such as this. There's too much ground and too many characters to cover in the second half of the season.

To catch up on the Reichenbach storyline, watch Elementary online.

Are you glad to have a self-contained episode?

What did you think of the case of the week?

Will Joan catch up that Sherlock is withholding information from her?

Comment below.

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