Sunday's Mad Men, "Favors," was written and filmed a long time ago. So it's just sheer coincidence that parts of it felt like such a deliberate and direct rebuttal to the many crazy fan theories that have been floating around the internet over the past few weeks. Is Megan Draper dead? Not unless her ghost can interact with Sally, Mitchell, and Dr. Rosen. Is Bob Benson a murderer? Not unless being rejected by Pete Campbell has left him so distraught that his character arc is about to take a dramatic turn.

But with just two episodes left in the season, Sunday's episode does leave one major theory on the table: Will Don Draper face a major medical crisis — or even death — before the sixth season ends? As Ted Chaough's wife says, God can turn off the lights at any time. And if Don's number is up, he'd better hope his attending physician isn't Dr. Rosen, who's dangerously close to sniffing out Don's affair with Sylvia (though he doesn't know it yet).

"She's doing that a lot lately. Lying about little things," Rosen says to Don over drinks. "I can tell she's been doing it a lot all year." But instead of taking Rosen's unintentional warning as a sign to back off once and for all, Don doubles down on the affair, with immediate and disastrous results.

When Megan suggests that Mitchell Rosen could flee to Canada to evade the draft, Don replies that Mitchell "can't spend the rest of his life on the run" — dodging the fact that he's spent the vast majority of his own life doing exactly that. And Don, in his attempt to save the life of Arnold and Sylvia's child, ends up destroying his relationship with his own.

Don's standoff with Sally in the hours after she discovered him in bed with Sylvia ranks among the series' most tense and harrowing moments. Director Jennifer Getzinger, who has helmed some of Mad Men's very best episodes — including season three's "The Gypsy and the Hobo" and season four's "The Suitcase" — did stellar work on "Favors," making the familiar Draper apartment feel unbearably claustrophobic. Sally Draper has been underutilized in Mad Men's sixth season, but there's real tragedy in her discovery of Don and Sylvia in flagrante delicto, which echoes her discovery of Roger Sterling hooking up with her step-grandmother in last season's "At the Codfish Ball." In her attempt to cover up the minor embarrassment of her own romantic interest in Mitchell Rosen, Sally has been unwittingly exposed to the deeply dysfunctional sexual escapades of the so-called adults in her life.

In many ways, Sally's genuine horror at what she sees proves her to be more of an adult than her father, who has spent much of the season showcasing just how undeveloped and petty he really is. In last week's episode, Roger Sterling told Don that he'd diagnosed himself as a "curious child" in a 58-year-old man's body, and his immaturity apparently extends to the rest of Sterling, Cooper, and Partners. It's no mistake that the central professional conflict in "Favors" is between the Ocean Spray and Sunkist accounts; since the two firms merged, both sides have been squabbling like children fighting over a juice box. "I don't want his juice, I want my juice," whines Ted, who eventually gets his way — but only by offering a distinctly unprofessional swap that will get Mitchell off the hook before he's drafted and shipped to Vietnam.

At the end of "Favors," Don seems to reach a reluctant détente with both Ted and Sally, though the excuse he gives his daughter — "I know you think you saw something. I was comforting Mrs. Rosen. She was very upset. It's very complicated" — is pathetically unconvincing. Don has been reckless before, but Sally's disgust might be the rare event that actually leads him to change.

With only two episodes left in the season, I'm hoping Mad Men has enough courage to take the nuclear option that it's been dodging all year: Allow Megan to discover Don's extramarital dalliances. From a logical perspective, Don has been far too careless for someone as intelligent as Megan to remain oblivious; from a storytelling perspective, Mad Men badly needs to break some new ground to prove that Don's latest affair isn't just a retread of the many, many affairs we've seen him embark upon since the beginning of the series. Will Don Draper's myriad sins finally catch up with him before the season draws to a close? Mad Men's sixth season began with Don reading Dante's Inferno — and every episode draws him further away from the straight road, and closer to the moment when he'll find himself alone in a dark wood.

Read more Mad Men recaps:
* Mad Men recap: 'A Tale of Two Cities'
* Mad Men recap 'The Better Half'
* Mad Men recap: 'The Crash'
* Mad Men recap: Fifty Shades of Draper
* Mad Men recap: 'For Immediate Release'
* Mad Men recap: 'The Flood'
* Mad Men recap: To have and to hold
* Mad Men recap: Sex, lies, and a ketchup account
* Mad Men premiere recap: Death and 'The Doorway'