Addiction is the dominant theme in this episode. It weaves its predatory way through SCDP's decline, Midge's heroin habit, and even Glenn and Sally when he offers her a cigarette.
SCDP is having no luck drumming up new business because prospective clients smell their desperation and fear the agency may go under in six months. They cancel meetings last minute and if they do show up, they don't even make it to ordering the first cocktail. New business is vital to the agency's survival and without it, SCDP will go from "stagnant" to "decaying."
Don pens a decree against tobacco and SCDP's involvement with selling it. Without consulting his partners first, he takes out a full-page ad in the New York Times. But his Jerry Maguire moment is hardly altruism. As Megan tells him how much she loves the ad, Don belittles her with his retort, "Megan, that's not what it's really about."
"It's about 'He didn't dump me. I dumped him.'" She can see through him and it's refreshing that one of his secretaries is standing up for herself after putting herself under him.
Don isn't one to have a crisis of conscience -- he's as opportunistic with the ladies as he is with business. The agency needs to shower off the stench of desperation and his move is merely public relations.
Midge from Season One randomly appears, looking thinner than usual (ever "the starving artist," she claims), in the foyer of the SCDP building. Don's former fling (and first of the Series) says that she's just returning from a meeting with another firm in the building. She lures him back to her place under the guise of potentially buying a painting but her "idiot" husband reveals that she's actually tracked him down, not to rekindle and old flame, but to ask him for money for her heroin habit. While Midge freshens up in the bathroom, her husband works on Don, trying to sell him one of his wife's paintings, and then her body by saying, "She digs you and I could tell you she'd do anything if you bought one... we're not possessive." It's all the sob-story trickery of the addicted -- "I lost my purse," "I just wanted you to buy a painting," give me money and "I'll cook us some chicken cordon bleu."
Midge explains, "I know it's bad for me... but it's heroin, Don. I just can't stop." Don once again becomes just a man in a room with checkbook, paying for his sins by quietly covering Pete's 50k contribution to balance SCDP's expenses, and then, out of pity, he buys Midge's painting -- first with a $300 check that she cannot use, and then with $120 in cash.
She then asks him, "Think my work's any good?"
"Does it matter?"
After staring at her painting, this dialogue is later echoed in his full-page tobacco dismissal: "For years we dedicated ourselves to peddling a product for which good work is irrelevant."
The ad continues, "Because people can't stop themselves from buying it. A product that never improves, causes illness, and makes people happy.... Our entire business depended on it. We knew it wasn't good for us but we couldn't stop."
Though all of SCDP's employees seem to be impressed with Don's "f*ck you" to Big Tobacco, the partners are furious. Pete yells "It's suicide!" Cool-tempered Lane says "No one asked you to euthanize this company." Bert Cooper says he's "humiliated" and then resigns, yelling for someone to "get my shoes!" Ridicule comes in the form of Don's arch nemesis, Ted Chaugh, who prank calls him pretending to be Bobby Kennedy and then thanks Don for the free publicity.
The ad also forces Dr. Faye to resign, as her company still wants tobacco cash. But always one to see how forgoing her career can bring she and Don closer, she's excited that they can meet out in the open because her leaving SCDP means "we can do that now." After a bit of kissing, Don says nothing except for suggesting a restaurant for dinner.
Now that Dr. Faye is gone, this makes his double dipping at the office a bit easier. But it looks like Megan will emerge victorious. As Dr. Faye and he meet in the conference room, Megan is seated at her desk, the camera framing her between them. While Dr. Faye waits for Don to tell him about her resignation, Megan is right alongside him. However, Dr. Faye suggests to Don that "his girl" make their dinner reservation, a vindictive move that would let Megan know about their relationship. 
There is another crisis happening in Ossining. Sally finds confidants in both Dr. Edna, the child psychiatrist, and Glenn, a child therapist her own age. She plays a game of Go Fish with Dr. Edna, playing with both the literal and metaphorical hand she was dealt. Through the psychotherapy, Sally has learned to deal with frustrations from Mommie Dearest.
"It's hard to control ourselves when we get so angry." Dr. Edna tells her and then offers the nurturing words that Sally longs for -- "I said I'm very proud of you, did you hear that?"
The psychotherapy sessions have benefitted Sally as she looks less prone to self destruction (and self-exploration)... for now.
And of course, Betty the little girl archetype makes Sally's therapy sessions about her. When Dr. Edna remarks on Sally's progress and how she can drop to one session per week, Betty becomes unnerved because it means SHE will see less of the doctor. Dr. Edna reminds her that she's child psychiatrist and though she first recommends a more appropriate colleague, she relents. "Why can't I talk to you?" Betty panics. She's got the infantile notion that the world revolves around her.
Sally finds a pal and confidant in Glenn (or as my friend likes to call him the 'creepy schoolboy'). They get together outdoors, away from the confines of their oppressive and hated homes. He offers her a cigarette, which she refuses ("I learned it from watching you, Dad" finally has a positive spin!), and explains that Sally's mom "doesn't like kids." Driving by in her smug daze, Betty catches them together and, assuming they're fooling around, forbids Sally from seeing Glenn. She tells Sally that she doesn't know anything about him. And yet, Glenn was Sally's only friend, and yes, sure he's creepy, but at least he was there for her and they explored some pretty deep thoughts and feelings.
Betty's tyranny extends to her suggesting that the family move away. Sally runs from the dinner table and Betty coldly dismisses her exit with, "She'll get over it." The poor girl cries in her room where she holds the keychain Glenn left for her after trashing the house in Episode 2. As Sally tells Glenn that she doesn't believe in heaven and her real fear is that death is forever, will she now self destruct?
What will happen with SCDP? Will they team up with the American Cancer Society and the powerful board members Ken mentions? Will Dr. Faye find out about Don's secretarial fling? Will Sally burn the house down? The season finale- - the climax and resolution wrapped into one episode -- is just a few days away.
Anti-Tobacco History fact:
Leave it to totalitarianism to restrict smoking -- Nazi Germany was the first country to enact a nationwide ban on tobacco advertising. I guess if you're the keeper of the master race, then better keep it from getting cancer. The practice was seen as betrayal to the goal of bodily -- and racial -- purity. Check out the ad below, which translates to: "He does not devour it, it devours him." 
And of course, the tobacco companies exploited this connection. In 1998, Philip Morris "If fascism comes to America, it will come in the form of a health campaign." Their 1996 European tobacco advocacy campaign "Where Will they Draw the Line?" equated tobacco restrictions with the Jewish ghetto. Click here to view the ad and read more about modern exploitation of Nazi anti-smoking policy.