Just because Sara recovered the Linares baby intact doesn't mean the job was done for her.
She still hunted whack-a-do, wanna-be mother Libby throughout The Alienist: Angel of Darkness Season 1 Episode 5 and The Alienist: Angel of Darkness Season 1 Episode 6.
She and her team (make no mistake it's her team) also discovered that Anna Linares and Martha Napp's baby weren't the only ones kidnapped by Libby.
It's a good thing that Sara can compartmentalize, long before it was fashionable, as things started to heat up between her and John right in the middle of all this.
How did Sara solve the case? By doing the legwork that NYPD should have done, had they given a crap about a Spanish infant being abducted when the U.S. and Spain were on the brink of war.
Sara was more concerned with reuniting a grieving mother with her child than politics.
It didn't hurt having spies inside NYPD in the form of the Isaacson brothers. So anything that the cops knew, Sara also found out.
Byrnes, and in turn NYPD, only cared about Libby because of what she had observed inside the Lying-In Hospital.
That, and for her brutal murder of the matron, Maureen. Sara even got to that crime scene first, thanks to a tip from Lucius.
By getting there first, Sara was able to observe the crime scene before NYPD arrived to kick her out and trample the evidence.
That enabled her to learn how dire baby Anna's situation was, since Libby was slowly poisoning her.
The brothers also passed along word about Colleen identifying Libby in a mug book.
Lucius, who appeared sweet on Bitsy, also stole the photo featuring Libby from the hospital, which Sara used to find out from Cyrus that Libby was Goo-Goo Knox's moll (there's just not much chance to use that word anymore).
It's amusing to observe the differences between the Isaacson twins.
Lucius practically cowered when he followed Sara into Maureen's apartment. He's your typical science nerd.
But later, Marcus drove off a duster menacing Kreizler with a knife by pulling a gun. He aspires to a more active crimefighting role.
It's hard to believe the Irish cops haven't caught on to the moles in their midst. But those thugs really don't give much thought to those Jews and what they're doing at crime scenes.
After all, it's not like Kreizler and company can fund their own forensics lab. Better to poach NYPD's scientists instead.
Sara even managed to attract another helper in Cyrus's saloon in the form of his niece Joanna. She performed admirably in an unfamiliar role.
However, I fear for her future, as Knox's dusters came after her for her connection to Sara and the others. Cyrus needs to lock that door during his off-hours.
Once Sara confirmed that Libby and Knox were still together, she knew where Libby was hiding out.
The tension built nicely as first Sara, then John crept through the boardinghouse's filthy cellar.
Of course, Libby got away. Otherwise, the series would be over already.
But, more importantly, Sara closed her first important case, returning Anna to her parents.
That wasn't enough for Sara, though, as having Libby still on the loose made her victory feel hollow.
So she doggedly pressed on, finding Libby's hidden nursery at the boardinghouse, then uncovering Libby's next target with John's help.
Hearst's attempt to smear her only led to more potential clients for Sara.
Didn't Sara use her leverage when she got it, forcing Vanderbilt to agree to get Kreizler reinstated and putting Byrnes in his place as her underling?
A master of publicity, Hearst sagely advised Byrnes to make the most of his time in the spotlight, but will Byrnes listen?
Maybe Byrnes will come to appreciate the way Sara and the rest of the team handle an investigation.
But probably not. Hopefully, he will cooperate and not interfere with the effort to catch Libby.
Finally, after the better part of two seasons, John and Sara got together. With the chemistry between them, this was inevitable.
As soon as she moved in, it would seem evident that there would be a breakthrough, especially after the high of finding Baby Anna. And it was a sweet moment, long overdue.
Then came the fallout.
John was all ready to play house afterward.
Fortunately, Sara's obsession with Libby kept her occupied, so she didn't have much chance to think about herself and John being a couple.
It's evidence of John's growth that the old whoredog felt guilty about sleeping with Sara.
I almost felt sorry for Violet. She had been presented as a rich, pouty airhead. But she has been given more depth now.
Apparently, she feels unwanted by all the authority figures in her life, so she's banking on marrying John to give her a sense of belonging.
The truth is going to hurt.
Laszlo also was in a world of hurt, after Pauly's magic trick almost went tragically wrong.
That gave Markoe and Byrnes the chance to shut down Kreizler. They have secrets they're hiding, so they'd better be careful who they piss off.
It's great that Laszlo now has Karen to give him some much-needed perspective.
To revisit Libby's reign of terror, watch The Alienist: Angel of Darkness online.
Were you at all surprised that Sara and John got together?
Why can't Libby just lie low?
Was Laszlo wrong to blame himself for Pauly's hanging?
Dale McGarrigle is a staff writer for TV Fanatic. Follow him on Twitter.