Plot: A murderer is sentenced to be mind-wiped. Talia has to scan him before and after to make sure it works, and has a creepy experience in the before. But before we get to the mindwipe, he manages to escape into the B plot with a PPG injury.
In the B plot, Dr. Franklin sets up an unauthorized free clinic Downbelow. He finds a former doctor healing people using alien technology, which transfers bits of life from one person to another. She doesn't mind giving up bits of life because she has a terminal illness. Then the murderer from the A plot shows up to get her to heal his wounds, but in self-defense she reverses the machine and kills him, healing her terminal illness.
In the C plot, Londo attempts to make friends with Lennier by taking to a strip club, then a game of poker. Londo is caught using his reproductive tentacles to cheat at cards, and the two get in a bar fight.
The Title Means: "... is not strain'd" -- Shakespeare, of course. But I'm not sure I see a connection to Shakespeare's meaning ("mercy is not something you can be forced into").
Comment: Is this first time the people Downbelow are called lurkers? I probably just missed a previous one. I remember when I started this series of posts I was pleased to discover the canonical resource for B5, the Lurker's Guide, was still online (and still in the pristine state so I could research people's guesses and interpretations as the episodes came out). But I actually didn't remember why it was called the Lurker's Guide! (Weirdly, IMDB predates B5. Just shows how old I am--a show I think of as being a long time ago actually postdates the web, meaning my sense of the age of the web is all wrong.)
Once again I left out a lot of subtlety from the plot summary, such as the female doctor (played by June Lockhart from Lost in Space--no shared scenes with Bill Mumy, though) regretting killing someone given her hippocratic oath, or the reappearance of the judge from "Grail".
So, as well as being a self-contained plot, the alien healing machine is a Chekov's gun--it will be used to save one character's life at some later date, at the cost of another (but is he really dead? I never saw season 5). Fortunately, because they designed it to have a significant cost, the writers avoid questions about why they don't use it all the time (a perennial problem in episodic sci-fi/fantasy series).
The fact that Londo (and all male Centauri) have tentacles, and they showed it on the screen, and then revealed them to (apparently) be reproductive organs makes it feel like a pretty weird one getting past the censors.
The big thing here, though, is The Demolished Man. This was one of Alfred Bester's two early and best-known SF novels. (Both are flawed, but I think The Stars My Destination is the stronger work, although The Demolished Man won a Hugo.) The Demolished Man is about an organization of telepath policemen, like the Psi Cops, which ends with the central criminal figure having his personality wiped and replaced with another one. (The most memorable part of The Demolished Man is the earworm-y jingle the criminal uses to make it hard for the psis to scan him, which as we all know, goes in part: "'Tenser,' said the Tensor.")
Obviously it is no coincidence that the antagonist Psi Cop in B5 is named Alfred Bester as well--brilliantly cast and played, as Shaenon explained in her Mind War recap, by Walter Koenig (Chekov from ST:TOS). Although Bester is not in this episode--he's only in one episode this season--he reappears throughout the series (as well as receiving mentions in other episodes in which he doesn't appear, as in "Eyes").