Do you remember the climax of Agatha Christie’s “Murder on the Orient Express?” It turned out all the murder suspects were guilty.

And as Trump’s handpicked ambassador, Gordon Sondland, publicly declared during Wednesday’s House impeachment hearing, all the suspects in the illegal scheme to squeeze Ukraine for fake Biden dirt are guilty. Starting at the very top, with Trump.

And Sondland is certainly a credible guy, right? After all, Trump praised him last month as “a really good man and great American.”

Here’s what the good man and great American told Congress: “Everyone was in the loop.” The whole mission was to “make the boss happy.” And if it made the boss happy to hold back taxpayer-financed military aid from an ally fighting Russian aggression, until the ally agreed to launch bogus investigations of the Bidens, then fine. In Sondland’s explosive words, “Was there a quid quo pro? The answer is yes…We followed the president’s orders.”

Translation: I paid a million bucks to get myself an ambassadorship, and never imagined I’d get sucked into something like this. There’s no way I’m gonna take the fall. If that happens, I’m gonna take everyone down with me – starting with Trump.

Sondland’s sworn testimony – at least for those of us who aren’t “bored” by these proceedings – is more delicious than a chocolate sundae. Historians will look back on this day as conclusive proof that Trump blatantly abused his office, pursuing his own personal interests and solicited collusion with a foreign government – all at the expense of our national security. And as Sondland testified, “everyone was in the loop” on the impeachable act.

Sondland fingered Secretary of State Mike Pompeo, ex-national security advisor John Bolton, acting White House chief of staff Mick Mulvaney and, of course, he fingered Rudy Giuliani. In short, “everyone knew what we were doing and why.”

Am I overreacting? I’ll yield the floor to Ken Starr, the conservative Clinton-hunting special prosecutor. On Fox News Wednesday, he said: “Articles of impeachment are being drawn up if they haven’t already been drawn up…This, obviously, has been one of those bombshell days.”

Sondland also blew up two desperate Republican defenses. The mantra of “no quid pro quo” is dead. And the notion that Rudy and a handful of confederates “went rogue,” and that Trump had no role in the scheme for fake Biden dirt, is buried.

Now for the fun part: Sondland was quizzed about his cellphone conversation with Trump on July 26. Sondland was at a Kiev eatery when a foreign service official, David Holmes, has already stated in a sworn deposition that he was with Sondland at the time, that he overheard Trump’s end of the conversation (because Trump was speaking so loudly), and that Trump specifically asked Sondland for an assurance that Ukraine would indeed launch a Biden dirt investigation.

Sondland, today: “I have no reason to doubt that the conversation included the subject of investigations.” And “I have no reason to doubt” Holmes’ recollection of the cellphone call.

Holmes, in his deposition, said that Sondland assured Trump that Ukraine’s president was ready to play ball – and that, in fact, “he loves your ass.”

Sondland was asked whether he really said that. His response: “It sounds like something I would say.” He and Trump talked frequently, and liked to engage “in Trumpspeak,” which featured “a lot of four-letter words” – or, in the case of ass, “a three-letter word.”

(So they spoke a lot? But didn’t Trump say earlier this month that “I hardly know the gentleman”?)

Looking back, Sondland now laments: “I really regret that the Ukrainians were placed in that predicament.” It’s nice that he feels compelled to voice remorse. And it’s amazing how his memory keeps getting better as the noose keeps tightening. Luckily for us, he has zero interest in taking the fall for a crime boss.

Indeed, Trump knows how that game works. Last year he told Fox News: “I know all about flipping. For 30, 40 years, I’ve been watching flippers.”

In Trumpspeak, Wednesday’s flipper is beautiful.