Home invasion was a theme this week, what with Pima intruding upon Stan’s darkroom as well as his and Peggy’s deepest fears, Don strongarming Diana’s affections to the point that he was granted access to her private pain palace and Roger hammering the final nail into the coffin of Marie’s marriage. Then there was this:

There was something anxiety inducing about the Calvet girls picking through Don’s apartment. It wasn’t just that it unearthed old ghosts, although it did, at least in this viewer, a flood of memories both good and bad. It was that we didn’t know what they would find. What could they find though? After all, Megan knows all about Don’s past – this isn’t Betty rooting around in his draws in season one. Only somehow it all feels familiar, the same hint of impending disaster in the air.

If there was any doubt about the symbolic nature of Tricia’s wine stain then New Business puts all protestations to bed. Mad Men has a history of using these kinds of devices – remember the tear in Bobby’s wallpaper in The Flood which represented the absence of a stable, ordering father figure? – as metaphors for its character’s concerns. Here the gash-like stain functions in a similar way, standing in for the deep emotional scars inflicted by Don’s childhood. Scars that have never healed and from which there is a direct throughline leading right up to the present day, to Don’s sex mania and an air hostess spilling a drink on his floor. It doesn’t matter that Marie is ignorant of all this, it’s enough that she understands Don as a damaged person who damages those around him – which is all she needs to see this gaping wound for what it is.

Weiner and his staff could have made the stain anything, whisky, a cocktail, whatever, but they chose wine. Wine because it’s a woman’s drink, it’s bacchanalian and permanent. Sex – abandoned, chaotic behaviour – that never washes out. It will be there forever. It has been there forever. The stain is a doorway into Don’s dirty private life, which he never gave up even while married to Marie’s daughter. And it’s sitting there slap bang by her old marital bed, a grisly reminder of just how badly Megan was treated.

At the time though, it was invisible. Nothing was conclusive. Megan, to paraphrase Don in Time Zones, didn’t know… but she knew. A whiff of another woman’s perfume here, a late night disappearance there, too many client meetings – all the stuff that used to plague Betty’s thoughts. But in New Business there’s indelible evidence that someone else has been in Megan’s house. It doesn’t matter who, this woman has worn so many different faces, what matters is she was always there, lurking out of sight.

Don’s nightmare in Mystery Date ended with him murdering his dream lover, another home invader, and depositing her under the bed. He was that afraid of his old, wild nature returning. But at last the blood has trickled out, the crime scene laid bare, the criminal exposed.

At the end of New Business his apartment, his life, is gutted.

Only the stain remains.

*Marie Calvet, New Business