You gotta love a system of governance where the success of a key piece of legislation, the career of a prime minister and possibly, you know, the fate of the world can be altered by a guy deciding to change seats in the middle of a speech.

But then, this is why British television is currently the best binge in town. I’m not talking about the “Downton Abbey” movie or the return of “Happy Valley” or even this year’s glorious “Years and Years” (though more about that in a minute). I’m talking about the greatest British show of the 21st century: The great Boris “Brexit” Johnson meltdown.

It’s been running for at least a week, enthralling U.S. audiences that always love a good British drama and frankly need a break from their own Twittering nabobs of negativity.

Last week, Johnson, the famously brash and publicity-loving former mayor of London and newly installed prime minister, asked the queen’s permission to suspend Parliament beginning Sept. 9 to neutralize those opposed to his plan to remove the United Kingdom from the European Union by Oct. 31, even if there is no deal in place.

As any fan of “The Crown” can tell you, such requests are strictly pro forma: The queen has no legislative power in Britain’s representative democracy, so her answer was always going to be some gracious version of “fine, whatever.” Still, the headlines — “Queen Grants Johnson Permission to Suspend Parliament” — were pretty darn good, and it’s nice to see any mention of her majesty that did not involve her husband’s horrific driving habits or the whole William versus Harry, Kate versus Meghan situation.

In the actual world, Johnson’s move outraged many pundits, some of whom had secretly hoped the queen would find a loophole in Britain’s unwritten constitution and can Johnson altogether, and even more citizens, many of whom demonstrated in London and shouted “Stop the coup” at Johnson when he spoke Monday in front of 10 Downing St.

So we knew the next episode was going to be good. (One note: Someone might want to get the British Constitution in writing.)

Though lacking the fabulous robes-and-wigs factor of the British court system (featured prominently in Emmy nominee “A Very English Scandal”), Parliament often makes for good TV. There is inevitably a lot of jeering and cheering, paper crumpling and file hurling in the House of Commons; briefcases and podiums are pounded and calls for order ignored. All this from the representatives of a people continually portrayed, at least in romantic comedies, as victims of culturally inflicted stoicism struggling to connect with their feelings.

They connected with them on Tuesday.

As Johnson debated opposition leader Jeremy Corbyn before a wildly grumbling Parliament, in advance of a vote on legislation that would have allowed Britain to leave the European Union without a deal in place — pledging that he would free his country from the stifling confines of the EU come what may — Phillip Lee stood up from his seat with fellow Conservative Party members, walked across the floor of the Commons and sat down with the Liberal Democrats.

Johnson kept on talking, but with Lee’s defection, he lost his majority — and, later that day, lost the vote.

In the words of many media platforms, a “rebel alliance” had seized control of Parliament. Seriously. Like there were Jedi involved.

Johnson responded by saying that if the House of Commons voted Wednesday to make a no-deal Brexit impossible, he would be forced to call for a general election next month, and who would be happy about that? Nobody, that’s who.

Oh, and he then expelled from the party the 21 Conservative members of Parliament who had voted against his legislation. Including Nicholas Soames, Winston Churchill’s grandson.

Winston Churchill’s grandson. Surely expelling him violates the Geneva Conventions or something. (Although, as many immediately pointed out, Churchill grand-père switched parties a few times too.)

By late Tuesday afternoon, the only thing trending harder than Churchill was now-Member of Parliament Theresa May’s perceived smirk when Johnson’s power play blew up in his face. (And she voted for it.) Johnson’s battering-ram approach was clearly not popular, and Parliament rejected it.

Obviously, this turn of events is important, both in terms of Brexit and the context of world politics, which seems fueled by the same “us versus them” mentality that democracy was purportedly invented to dispel.

It also may be one of those times when fact met fiction and, with the help of a sonic screwdriver and “Doctor Who” shimmy, changed the course of history.

While Boris versus Parliament is not at quite the same crisis level as, say, the Doctor and the Daleks, it does have a fictional counterpart: In HBO’s “Years and Years” (see, I told you I’d get back to it), Russell T. Davies seems to have magically predicted the Boris Brexit smackdown. The series imagines a slightly futuristic Britain that, distracted by the cheap thrill of rhetorical division and the grind of daily life, gradually slides into a nationalistic hell overseen by a blunt-talking charismatic politician. It is a mild dystopia, as dystopias go — no alien overlords or mass extinction via asteroid — except that too many people are being greatly harmed in a way that is completely believable. As in the real world, some of the characters find politics “as usual” quite boring, and most don’t understand the granular ins and outs of even their own system of governance. It’s much easier to vote or not vote, to act or not act, based on some personal feeling about this or that leader. Only when things get really out of hand are ordinary citizens galvanized.

As an American, I know a little about this, though obviously I have no say in Brexit. But polls indicate that, at best, the country is evenly divided, with some suggesting that more would prefer to remain in the EU than to leave it.

By press time on Wednesday, a bill to block a “no deal” Brexit had passed the House of Commons and will proceed to the unelected House of Lords, which can pass the bill or send it back to the Commons with amendments. Later, Johnson faced yet another setback, as his motion to dissolve Parliament and call a snap election for October failed to reach the required two-thirds majority. The next installment of the drama is unclear, but whatever it is, the world will be watching.

The arc of history may, as the Rev. Martin Luther King Jr. said, bend toward justice. But sometimes it takes a big dramatic jolt to get us there. Or just a guy switching seats. Either way, the next season of “The Crown” has some pretty dramatic shoes to fill.