Back in the 1980s the once preeminent American sitcom Happy Days was plummeting down the popularity charts at such velocity that the panicking producers got the hero of the show Fonzie to don water skis and leap over a shark. A moment of madness that, naturally, didn’t work.

Ever since then when an ailing programme loses the plot by desperately attempting to revive its fortunes with a ludicrous publicity seeking stunt it stands accused of “jumping the shark”. Which brings us to the deranged double drowning on EastEnders.

Of course, it was unfeasibly melodramatic for both Mitchell sisters to meet their maker in a swimming pool on Ronnie’s wedding night. But, hey, that’s the soaps for you. Never knowingly not absurd. If you want realism, you won’t find it in Albert Square. Ever. So no complaints about the basic concept of this eye-catching tragedy. Standard issue moronic ratings-chasing.

But once the Beeb’s top team had decided to bump off TV’s barmiest blondes on New Year’s Day they appear to have become so intoxicated with the brilliance of their idea that they ditched all semblance of plausibility and threw cogent narrative into an abyss of disjointed madness. It was hilariously ridiculous.

Even before that fateful late night dip it was hard to keep up with the craziness. We’ve all been laughing for weeks over Jack and Ronnie’s impossible dream of moving to the faraway paradise of Ongar, a whole ten miles from the East End. Would Roxy go with them? Would she relinquish her parental rights over Amy to allow her daughter to flourish in her exotic new environment? Would Jack and Ronnie adopt her? Oh, the turmoil.

Welcome to the wacky world of Walford, where the strange agoraphobic locals regard nearby Essex as a different planet. And so it was that Ronnie wept as she begged Roxy to come with them to the promised land and Roxy sobbed as she refused on the grounds that she would ruin their brave new life. This was depicted as the ultimate selfless gesture. As opposed to the dereliction of duty of a deadbeat mum.

Come the wedding day on the unlikely date of January 1st, barking Roxy had upped the ante by bafflingly insisting that even to attend her sister’s marriage would wreck everything forever. No one could work out why. Least of all the long-suffering viewers as they were deluged by dire dialogue that threw no light whatsoever on the thinking of these disturbing oddballs.

In the end, with hospitalised thug Phil unavoidably detained, Rox generously agreed to give Ron away and they drove to the Brocket Hall venue in a vintage red Mustang sports car as if they were starring in a Poundland remake of Thelma & Louise. Derivative drivel.

The ceremony itself went surprisingly well with none of the contrived last minute hitches we’ve come to expect to be bored by. Then a spot of group Cockney knees-up dancing revealed that this was not exactly a packed non-event. If you choose to stage your nuptials on the day when everyone is nursing a major hangover you may well find that, funnily enough, not many people will turn up.

Meanwhile, with seconds to go, loony landlord Mick Carter announced to Jack that he couldn’t be best man because he had to go to the Queen Vic to listen to his weird liar son Lee’s pub robbery confession. F-a-a-m-l-e-e innit. As in… c-r-a-p  f-a-a-m-l-e-e. If you’ve been affected by Lee’s stupid story… there’s something wrong with you.

Back at Brocket Hall the insanity was really soaring into orbit. Instead of launching married life in the bridal suite, Ronnie grabbed two bottles of champagne and told her hapless husband she’d return presently. Grounds for immediate divorce. But thinking nothing of it, Jack invited his two kids into the marital chamber and read them a bedtime story. On his wedding night. Really.

Charmed by her sibling’s kind invitation to sit on a bridge in the middle of winter, Roxy left Max Branning in her room with her handbag and stash of cocaine. No sex for poor Max, who was in for a lengthy wait.

After the sinister sisters quit the bridge and headed for the indoor swimming pool, the grim reaper was ready to do his worst. How did the Mitchell girls actually drown? In a blurry sequence of drama-killing arty images that spectacularly failed to tell the story. And then there they were… a couple of Barbie dolls floating in the deep end. Ronnie in inappropriate white, Roxy in black. The end of an error. Pass the Kleenex.

Unperturbed by his new wife’s night-long absence, Jack slept soundly with both children in his arms. Only when he was awoken by the police did he begin to suspect something might be a bit amiss. Same deal with Max, who, despite being alone on gone-girl Roxy’s bed, enjoyed an unbroken night’s rest. The Branning brothers suffer from the opposite of insomnia.

By now the bad news had reached Albert Square and Sharon raced to the hospital to break it to Phil that his cousins were brown bread. The possessor of an unenquiring mind, Phil didn’t ask how they had croaked. He simply made a toad-style guttural noise and his eyes went wet. Give him an Oscar.

Collateral damage included new-headed Michelle’s meat pie dinner which, due to unforeseen circumstances, the late Roxy and Ronnie’s relatives were unable to attend. And the happy couple’s welcome home party which, thanks to the bride suddenly being indisposed, never really got off the ground.

The fact that this arrant nonsense pulled in the biggest audience for a year may not be such a good thing. It means that 7.6million people got to see how rubbish it was. I’m guessing a fair few who endured the disastrously dotty demise of two stalwart characters won’t be tuning in again. Who wants their intelligence insulted with this kind of brainless claptrap?

But, for all their faults and their chronic inconsistency, R & R will be sorely missed. They had some genuinely memorable moments.

Ronnie – the alleged stable one – murdered two victims and stole Kat’s baby in an offensive plotline that the BBC was forced to axe amid a storm of furious protest from fuming fans who, unlike the space-alien scriptwriters, understood motherhood.

Roxy – the drug taking promiscuous one – landed a series of high-flying jobs (spooning out postman Masood’s curry at the market, helping midget Donna flog tatty clothes etc.), married Alfie Moon for a day and was once a multi-millionaire. For at least 20 minutes. No one could ever work out how she spent all her money. She simply went to the cash machine and there was none left.

In the spirit of sisterly camaraderie, they both slept with Jack and had babies by him. And it’s that guy I feel truly sorry for. He’s run out of Mitchell girls to knock up. For now. Lest we forget, Louise is fast-approaching the age of consent. Watch this space.

Farewell then Ronnie and Roxy Mitchell. They jumped the shark way too often. Even in death. We shall not see their like again. Hopefully.