After what felt like forever, (almost 2 years in fairness) 'Catastrophe' returned last night for what will be its final ever season. The Channel 4 sitcom, written by and starring Sharon Horgan and Rob Delaney, is easily one of the funniest shows we've had on the box in years and last night's opening episode proved this dysfunctional-functional couple have not lost their touch.

Other seasons may have taken a time jump but season four picked things up with Rob and Sharon pretty much where we left them, with a car accident forcing Rob to admit to his wife that he was back on the booze again. Rob is faced with community service in a cerebral palsy charity shop while Sharon is tasked with keeping the kids entertained on her own at the weekend. This leads to her own "garden variety cry for help" as Sharon starts switching price tags on items with son Frankie ultimately ratting her out in a moment that could have been straight off Horgan's other recent co-written comedy 'Motherland'.

What 'Catastrophe' is all about though is the dynamic between Rob and Sharon, who are going through the hardest of their hard times together as Rob tries to get his life back on track and Sharon struggles to trust him again. It's all very raw and real this time around and they're visibly struggling to cope in a way that's a little more unsettling than in previous seasons.

Still, in the midst of this comes the superb comedy writing of Delaney and Horgan, who can manage to completely diffuse any tension with just one-line. "I want you to stop farting your guilt on to some lady", Sharon tells Rob, after he finds himself getting entwined in the life of fellow AA member Amanda, who he describes as looking "like she was transforming into a mouse and got interrupted". Amanda, played by the always fantastic Julie Hesmondhalgh, also gets to sweetly tell Rob that he should "try to get better" and "not wank off to your little man feelings”. This comes after he tells her he has been listening to Radiohead.

So yeah, 'Catastrophe' can still deliver the goods with it's comedy timing, even in moments with no dialogue - Rob still has Sharon saved on his phone as 'Sharon London Sex'. And as much as these two may look like they're in trouble, the heart of this show has always been the tenderness that's clearly brimming under the surface of the acerbic wit of their unfiltered relationship. Nothing too sentimental here; "Just don’t die on me. The kids would be f**ked if you die first", Sharon tells him. And then they go at it doggy style as Sharon can't take him seriously with his neck brace on. If that's not love...