The only time Nigel Farage and Russell Brand should meet is at the speed of light in the Large Hadron Collider. But meet they did on the BBC's Question Time, a programme inspired by the phrase "exercise in futility".
So close did they get that Farage, leader of the populist Eurosceptics Ukip, said he saw Brand's personal make-up artist straighten his chest hair for him.
Farage calls Brand a political lightweight, a "chest-hair obsessed Hollywood type", the "messiah of hipster, new media".
Brand calls Farage "worse than stagnant", a "tribute act", and "an infinite cricket green".
Both of them are right. But there's something odd and - quelle surprise - hypocritical about Brand's take on Farage.
Comedian Brand's struggle against addiction to drugs is well documented. He says society should be more understanding of addicts because addiction is a disease.
So it's odd that he would imply Farage is an alcoholic as a means of trying to shame or discredit him.
"Nigel Farage in the flesh, gin blossomed flesh that it is, inspires sympathy more than fear ... who like many people who drink too much has a certain sloppy sadness," he wrote.
Though they might not like to admit it, Brand and Farage have a lot in common. Both draw on populism, play loose with facts and details, and are theatrical performers.
Both offer up a platter of reheated ideas: Farage, with his political Luddism, a prim social conservative who wishes progress would not simply stop, but reverse until it hits the 1950s again; Brand a pseud who wraps up ancient mysticism and 1960s anarchism in shiny new paper.
They both point at Westminster and shout "corruption" and "broken politics" but offer simplistic, idealistic, and romantic answers to complex constitutional, economic, and cultural questions.
They're sideline demagogues with megaphones, who can loudly hurl abuse and criticism because they don't actually have to do anything like take difficult political decisions that juggle the imperfections of liberal democracy.
And so Question Time is the perfect platform for Brand and Farage. It's a show for venting and ranting, not enlightening. No minds are changed. Pre-existing prejudices are solidified. It's a game of words, where panellists duel with rhetoric for the audience's favour. Question Time is to politics what Miranda is to comedy: bland, dull, obvious, repetitive.
Both Brand and Farage admit that their appearance together on Question Time had been anti-climactic. Viewers were expecting a fight to the death, but they didn't get it.
Missed opportunities are common throughout history: Lenin's final but undelivered letter for the Communist Party's congress denouncing Stalin; various failed assassination attempts on Hitler; the Pilgrimage of Grace, an armed Catholic movement which unknowingly had the upper hand against Henry VIII and could have toppled him had they realised before losing their guts.
And the time Nigel Farage and Russel Brand were in the same room together, yet no-one entombed it with impenetrable concrete, will go down as one of those missed moments in history.