"Your street value has declined. We're old now, and you have kids."
Fergal's advice to his sister is blunt, but it also underlines the theme that's made this season of Catastrophe so emotionally trying: You can't go back to the way things were. Sharon and Rob's lives changed irrevocably the moment they decided to keep Frankie, and much of this season has centered on them dealing with the fallout of their decision to create a family together. The season finale sees Sharon and Rob regressing back to their past selves, but their antics are horrifying and depressing due to the simple fact that, well, they're old and they have kids.
Both Sharon and Rob are seething avatars of indignation when this episode opens, shortly after Rob tells Sharon about what happened with Olivia. Catastrophe smartly leaves that revelation and its immediate aftermath in the gap between episodes, bringing us back into the action as the two attempt to forge lives separate from each other. It's hard, though — impossible, really — since the kid keeps them in each other's orbits, within easy striking distance of each other's barbs. (One thing you gotta love: Even in the midst of a dying marriage, these crazy kids can come up with ingenious fake email addresses for each other. Shout out to email@example.com and firstname.lastname@example.org.) Sharon has blown Rob's infidelity way out of proportion — he's either in the midst of a "sexual-harassment trial" or is "under house-arrest for sexual assault," depending on whether you ask Melissa or Mia — and Rob is deeply offended by her reaction.
Fran and Chris, who've functioned as mirrors to their friends all season, give Sharon and Rob respective come-to-Jesus talks, which both boil down to, "Get over it and hang on to what you have with each other," citing their own marital regrets as evidence. It's almost enough to get Sharon and Rob to settle down and apologize to each other, but neither will fully claim their destructive actions. Sharon's half-assed "I'm sorry for some of the things" and Rob's refusal to placate her leads to a bona fide row — albeit a quiet one, since Frankie is listening — during which the deeper, festering issues between them come to light. What Rob sees as "a fidelity traffic violation," Sharon sees as him keeping some "escape-hatch pussy at the ready," a manifestation of his inability to fully commit to his new life as a grown man with a wife and child. And what Sharon sees as Rob being too afraid to tell Olivia off, Rob sees as a projection of the pleasure Sharon seems to take in being disliked. ("You exude black squid ink!" is his poetic take on her general demeanor.) In short: Rob wants too much to be liked, Sharon enjoys being mean too much, and neither is willing to consider how that behavior affects their spouse and their marriage. Sharon and Rob both need a full-on death spiral before they can bring themselves to eat crow in front of each other.
And death spiral they do, in two very different but equally affecting ways. This whole season has quietly built toward Rob's relapse, and this episode piles on the temptation by having him shack up with Dave while he's in the middle of a drug binge. Dave is very accommodating of his friend's parental needs, refusing to do coke in front of the baby — just Krokodil — and consuming all the drugs in his house so it's a safe space for the kids. But Dave's too deep into his own spiral to see what an unsafe space his home is for his friend. Rob spends his time Googling "is alcoholism a myth" and lovingly stroking the glass breasts of a novelty liquor bottle, so it's no surprise that when he does finally bail on Dave to check into a hotel, he makes a beeline for the minibar.
Sharon, meanwhile, is trying to convince herself she can reclaim the behavior of her pre-marriage-and-baby life without consequence. Of course, her decision to go out to a bar with a cougar divorcée named Kate (Eileen Walsh) is just as ill-advised and self-destructive as Rob's decision to hang with Dave. Sure, Sharon gets a sitter for the kids — the chronically indifferent Anna, making a welcome reappearance — but she's clearly not approaching her night out as a wife and mother. Despite her lack of respect for the young lad who hits on her — "Gross," she says, when he tells her he does "Crossfit, baby!" — she dives headfirst into the bad-decision pool with him, too black-out drunk to realize or care about the consequences. Although Sharon would never say as much, she needs an assurance that her street value hasn't declined, that it's possible to embrace her old social habits and be the person she used to be. And Kate, who exudes regret and desperation the way Sharon exudes black squid ink, functions similarly to Dave, both enabling her friend's behavior and making it seem less alarming in comparison.
Sharon and Rob's decisions are alarming, though, particularly when you remember their children are at home with a sitter who has a proven track record of drinking Heineken on the job. (Anna's indifference to being shamed for this is a pitch-perfect utilization of Lauren Socha's distinctive on-screen presence.) Rob's night culminates in a truly terrifying manner when he discovers an overdosing Dave, on whom he performs CPR and gets a fountain of vomit to the face as thanks. Rob immediately returns the favor, in a spectacularly disgusting (but oddly cathartic) gross-out gag that helpfully underlines Rob's rock-bottom, and then covers it in puke. Rob's regret and anguish over his evening is apparent before he's even sobered up. Sharon, however, doesn't realize the extent of what she did until later — when it may be too late to atone for it.
Rob and Sharon's mutually hungover park-bench reconciliation is the most emotionally trying scene of the series, as Delaney and Horgan radiate their discomfort with the things their characters aren't saying. Sharon has managed to get her head around Rob's behavior, and he apologizes, but doesn't tell her about the state he was in when he found Dave. And Sharon scoffs at the suggestion she may have slept with someone else while they were apart, not even aware that she's laying a foundational lie that has the potential to collapse their marriage. They sweetly joke about all the reasons they have to try to make things work — flats are really expensive, there's a new night noise in the house, the whole love thing, but mostly flats are expensive — and then reconcile, spontaneously and vigorously, while a park groundskeeper looks on. They say they love each other for what seems like the first time in forever. They're oblivious, or willfully ignoring, the truth bombs waiting to explode their marriage once more.
Catastrophe could have ended its season there, but as we learned last season, Delaney and Horgan love a good emotional cliffhanger. The post-reconciliation revelation that Sharon had sex with Nico (of course his name is Nico, and of course he has a band) turns their dance of apology and forgiveness on its ear. Now, Sharon knows she carries the potential to ruin things anew. What she doesn't know, apparently, is to get rid of the receipt for the Plan B she gets, which shows she really should have paid attention to Kate's story about her ex-husband discovering all her receipts for lube.
Catastrophe has yet to be picked up for a third season (sorry, "series") by the U.K.'s Channel 4, which produces the show. (Amazon just broadcasts it Stateside.) At this point, we don't know if we'll get to see what comes after that amazing look Rob gives Sharon in the finale's closing moments: A combination of confusion, anger, fear, and betrayal. In those brief seconds of flustered agony, Delaney telegraphs the emotional scars of everything these two have been through, and it's heart-stopping. Catastrophe ends this dark, twisted, brilliant season with a fuse burning down, then cuts to black just before the explosion hits. It's horrible and wonderful and downright mean. When it comes to these two, what else could we expect?