“House Training” is one of those perfect storm House episodes: fun and meaningful exploration of the central character, insight into some secondary characters, ties to past episodes, and a compelling medical mystery that takes an unexpected turn. Some of the most memorable episodes in this series involve a break from the usual structure, but as written by Doris Egan, this one doesn’t rely on twists or tricks, just wonderful characterization plus incisive and witty dialogue.

The entire premise of House is that the cranky doctor and his slightly less cranky team work with patients that other doctors can’t diagnose, so the usual techniques don’t apply. Pinning down the rare disease before the patient runs out of time often means they leap to treatment rather than tests — sometimes out of a conviction that their clever answer to the medical mystery is correct, sometimes as a quick and easy form of diagnosis.

From season one’s “Detox” we got the madness behind House’s method: “I take risks. Sometimes patients die. But not taking risks causes more patients to die. So I guess my biggest problem is I’ve been cursed with the ability to do the math.”

Finally, we get the human face of the other side of the math equation. As Foreman points out, the team has run out of time before. They’ve made mistakes before. But this time, their mistake is a direct result of business as usual.

Lupe (memorably played by Monique Gabriela Curnen) is the unfortunate patient of the week, a three-card Monte accomplice who freezes during a scam, unable to exercise her free will. “Maybe we can get Thomas Aquinas in for a consult,” House quips. As he philosophically points out, “What’s life without the ability to make stupid choices?” And this episode is full of them.

The lack of free will is a symptom of a transient ischemic attack — a quick stroke — and the team brainstorms a root cause, such as a clot, ADD, or a vasospasm caused by the patient’s stupid choice to use drugs. Chase toys with Foreman by rejecting the drug theory and implying Foreman is judging her because she’s a minority. In fact, Chase already has the negative tox screen results. House has trained him well.

We learn Lupe’s tragic backstory while House wanders off to investigate Wilson’s friendly conversation with a woman we learn is his second ex-wife. A high school drop-out, pregnant at 15, Lupe lost her baby to SIDS. But like the man with the limp, her tragic backstory does not define who she is, and Foreman rejects the information as irrelevant and continues to view her with some scorn.

The second Mrs. Wilson, Bonnie (Jane Adams), wants Wilson to take their dog. But Wilson is not only never home, he doesn’t have a home, he’s still staying in a hotel. Gee, too bad he doesn’t know any realtors who could sell him a condo. House loses interest in the Wilson reunion when he discovers Hector is not their former pool boy, but gains it back when he discovers what Wilson is doing on Thursday.

Cuddy, a bright woman, must have looked up “I got tickets to a play” in her House-English dictionary and found the “I want to see you naked” definition, because we learn she rejected House’s invitation at the same time as House learns she’d already accepted Wilson’s invitation to an art exhibit for that same night.

She also knows she’s a pawn between the two men. “You think you saw somebody else pick up a toy from the sandbox and suddenly you want it,” using imagery that not only nails House’s mental age, but his perverse nature, too. She tells him she needed a friend and went with the safe choice. “I’m not safe? Cool,” House grins before warning, not inaccurately: “James Wilson is never the safe choice.”

As House tells Wilson later, “If I can figure out where you keep going wrong, I can nip this Cuddy thing in the bud before she becomes the fourth ex-Mrs. Wilson.”

So House spends a good portion of “House Training” trying to uncover the mystery behind Wilson’s multiple marriage pathology. He seems largely unmotivated by concern for Cuddy or for Wilson, but rather by his own pathological curiosity.

Scenes of House quizzing Bonnie while purportedly condo shopping are intercut with scenes of Wilson and Cuddy at a definitely-not-Hockney exhibit while purportedly not dating. Bonnie reveals that she and Wilson started off as just friends, but his attentiveness was seductive enough that she ended up jumping him. “James Wilson, carefully calibrating his level of protectiveness for your individual needs,” she says. “Did you just compare Wilson to a tampon?” House asks.

Bonnie found Wilson attractive because of his endearing ability to be a good friend, “always there to support you, until one day he’s not.” House gives a shocked Wilson the questionable advice that he has to sleep with Cuddy before she gets hooked emotionally in order to break the pattern.

That pattern of being there until he’s not hasn’t extended to Wilson’s relationship with House — yet — though we’ve never seen the House-Wilson dynamic in the early stages of a Mrs. Wilson. Maybe it is that scenario House is afraid of, maybe he is seriously afraid Wilson’s relationship with Cuddy will detract from House being the focus of Wilson’s protectiveness. Maybe he’s just an ass.

We have seen the House-Wilson dynamic in the later stages of a Mrs. Wilson, when House’s neediness takes him away from his wife. “Damned if You Do” and “Honeymoon,” among others, showed us a glimpse of that. And that’s the big reveal provided by Bonnie.

She confronts him after she finds out he’s been wasting her time with the condo shopping, and tells him the source of her dog’s name: it’s an anagram of Dr. Greg House, combining her resentment of House with the dog’s habit of peeing on the carpet.

“‘Hector does go rug’ is a lame anagram,” House says. “Want a better one for Gregory House? ‘Huge ego, sorry.'” I can’t tell you how much I love that anagram. OK, maybe I can: I really love that anagram.

“You always needed him and he was always there for you,” she says. “I’m not saying you ruined the marriage, but you didn’t help.”

So whether he accepts the lesson or not, whether it’s the whole story or not, House has a key to Wilson’s failed marriages: it’s him. However, as he not very kindly points out, he’s not going to buy a condo because he feels sorry for her.

Fortunately House is only minimally involved in Lupe’s care, giving him enough time to annoy Bonnie, Wilson and Cuddy and solve his friend’s doomed cycle of marriages. Foreman takes the tacit lead on the case, and when he and Chase find a crack pipe in Lupe’s dodgy apartment, Foreman’s even more convinced that despite her protests she’s a drug user. He wants to tests her for arsenic poisoning until she vomits blood on his nice white coat and goes into respiratory arrest.

While Cameron and Chase discover a mass on the subsequent MRI, Chase casually points out that if she changes her mind about dating him, he’s still available, and he will continue to remind her every Tuesday. It’s a hilariously low-key pursuit that throws her off-balance. “No need to go on about it,” he shrugs sweetly as she sputters her objections.

The mass leads the team to an auto-immune disease, and while House ponders which it might be, wanting to pinpoint the solution to the mystery, Foreman impatiently, Housily, but boringly wants to skip that step and go to steroid treatment, since that’s standard for any autoimmune.

Among their similarities, House and Foreman share the desire to avoid their parents. “House Training” brings Charles S. Dutton back as Mr. Foreman, and Beverly Todd as Foreman’s heretofore only hinted at mother, who suffers from dementia. They’re in town for her 60th birthday, since he had refused to return home to celebrate with them. He hasn’t been home, in fact, for eight years.

She’s brought him a framed picture of himself as a little boy, back when he used to peek ahead to the end of his math books to marvel at what he’d know by the end of the year. “You wanted to look ahead to see how far you’d go. Now that you’re a grown man, I thought you’d want to look back to see how far you’ve come.” Foreman doesn’t like looking back though, and this episode is the evidence.

Lupe accuses Foreman of not liking her, but he points out that she doesn’t stand out from any of the other drug addicts he’s treated.

“People who quit drinking and people who lose weight, they think they’re better than the people that couldn’t,” she accuses. “Because you got out of the projects, you think that anybody who didn’t is weak and stupid. … The only difference between me and you is that I made some bad decisions and you made some good ones. “

“I’m not judging you,” Foreman says before judging what she’s done wrong and what she needs to do to pull her life together. Then he notices her yellow eyes, meaning her liver is shutting down and she’s going to die quickly unless they solve her case.

He comes up with a rare cancer, lymphoma granulomatosis, that brilliantly fits the collection of symptoms, and he easily convinces House that total body radiation is the answer. While Chase and Cameron debate against the dangerous method until a diagnosis is confirmed, Foreman points out that she’ll be dead before a confirmation is possible. Even if he’s wrong, the radiation will act against an autoimmune disease, too, so it’s a no-brainer. So he thinks.

He balks at trying to convince her to go with the risky treatment, though, since she doesn’t like him. House volunteers. “Foreman’s got personality issues so you’re going to step in?” Chase asks skeptically.

But House isn’t interested in smoothing things over, of course, he’s interested in why she dislikes Foreman, who House seems to find the most enigmatic member of his team. “He thinks he’s better than he is,” she claims, causing House to ask the unanswerable “how good is he?”

Before he can really hammer the point home, that Foreman’s just possibly good enough to save her life with this dangerous radiation treatment, she has another loss of free will attack, unable to decide whether to sign the consent, unable to decide between a pen or pencil, unable to decide between Sean Connery or Daniel Craig. I have those kinds of attacks all the time, but I call them being perpetually indecisive. They also don’t lead me to pass out and wake up to face total body radiation.

She’s right after all: Foreman isn’t as good as he and House think he is, not in this instance. A heart murmur and excruciating pain lead them to discover that she’s septic, and despite the absence of symptoms of an infection — no fever, a clear lumbar puncture — that’s what’s been attacking her organs. By performing the radiation, the team has destroyed her immune system.

“I’ll tell our patient we just killed her,” House declares, but Foreman wants to take the responsibility. First, though, he wants advice from the master, so he goes to Wilson. He instructs him on how to carefully calibrate his presentation of the bad news with the patient’s needs, and Foreman’s amazed at how he’s got it down to a science. Calculated compassion is Wilson’s secret weapon. This is why he’s not the safe choice — his calm surface hides rocky depths, while House’s rockiness is proudly exhibited on the surface.

Even before I realized this will be one of the rare episodes where there will be no further epiphany, it followed the usual pattern enough that I expected one. When Foreman touched her when delivering the bad news, as instructed by Wilson, I half-expected her lack of pain to be a clue. Sadly, there is no last minute save for Lupe.

Omar Epps does a beautiful job in this episode with Foreman’s pain and frustration, usually subtly expressed until he punches a wall walking out of Lupe’s room. He goes to Cameron for bandaging, but not for moral support. “I killed a woman. Don’t you think it’s appropriate I feel like crap for at least a little while?” he asks.

Ironically, that cements the fact that Foreman isn’t just a mini-House, but shares some of Cameron’s viewpoints as well. This scene had shades of her words in the season two premiere “Acceptance,” where she claimed that when a good person dies someone should be affected, and put herself in the role of that someone. In this case, Foreman is even more tightly bound to the patient, having caused her death.

As with season one’s “Histories,” where Foreman dismissed a homeless woman for the same reasons he initially dismissed Lupe, he comes around to sympathy in the end. This time, he recognizes that he was judging Lupe as a distancing mechanism. He tells her about his own bad decisions in the past, and the second chance he got by leaving home.

“If I’m not the smartest, not the first, they’ll figure out I’m not supposed to be here,” he says. He explains that the last time he was home, his last year of college, when his mother put her arms around him, “that was the last time I felt at home. I only put distance between you and me because I know there isn’t any.”

She acknowledges her poor life choices, explaining “I always thought I was young, I had time.” Foreman reaches out for her hand, and I had to reach out to wipe away my tears, damn him. He sits vigil with her because she has no one else, and she accepts it because she has no one else. Wilson sits vigil with House, and it’s hard not to think about the fact that he has no one else, by choice.

Though Foreman has stopped an equally frustrated but not emotionally attached House from performing more tests on Lupe in his quest to solve the mystery, he phones him to give the news that she’s died. So House performs an autopsy before Wilson uses his patented technique on her grandparents to inform them of her death and get their consent.

The solution is heartbreakingly ordinary. She scratched herself with a bra hook — I knew those bloody things were deadly — and died of a simple but uncharacteristically presented staph infection. “That and some bad decisions,” House tells Wilson.

Chase the former seminary student failed to cheer Foreman up with the offer of drinks, so offers instead prayer as his coping mechanism. House less sincerely tells him to turn to religion, or giving alms to the poor, before “comforting” him that he’ll kill again, in the same way, because that’s the nature of their specialized practice.

It’s a battle of the expressive faces as Hugh Laurie and Omar Epps show down across House’s desk, both characters despondent over the outcome of their case but differing in their acceptance of the reasons behind it. House repeats the message from “Detox” that they save more lives because of their methods. “You’re giving me numbers,” Foreman complains. “Because they don’t lie,” House replies, before saying there’s nothing to forgive.

“Guilt is irrelevant,” House repeats to Wilson. But he then reveals he’s got a dog waiting at home, and what’s that about, if not guilt over Bonnie?

I’ve always thought of the concept of House getting a puppy as a metaphor for House getting soft and cuddly and the show entering a death spiral. But House getting Wilson’s cast-away old dog that is, apparently, as cantankerous as House himself, is not that metaphor. This could be interesting.

“House Training” doesn’t end on the funny, but the heartbreaking. After rejecting any form of comfort from his colleagues, Foreman goes to his mother, who instantly gives him the forgiveness he craves and wraps him in her arms. Because of her Alzheimer’s, she also has no idea who he is or what she’s forgiving. The only sense of home he remembers is ripped away, and the anguish of it is apparent on his face, pressed into his uncomprehending mother’s shoulder.