President Trump referred to “Mr. Elegant.” Was he referring to TV journalists Lester Holt, top right, or maybe Chris Wallace?  (Photos, from right: by Jabin Botsford/The Washington Post; by José Luis Villegas/The Sacramento Bee/AP; and by Joe Raedle/Pool via AP.)

It sounds like something out of the game Clue: It was Mr. Elegant, at a debate, with … tax-policy talking points?

President Trump has created a mystery worthy of the classic board game by dropping an inscrutable reference to a man he calls “Mr. Elegant” during his meandering interview with the Wall Street Journal, the transcript of which was released in full by Politico on Wednesday.

The president, while answering a question posed by WSJ editor-in-chief Gerard Baker about the aims of his upcoming tax reform effort, launched into what seemed to be an attempt to quantify the amount of money that companies spend offshore that he wants to return to the United States by lowering corporate taxes.

We have — nobody knows what the number is. I mean, it used to be, when we talked during the debate, $2.5 trillion, right, when the most elegant person — right? I call him Mr. Elegant. I mean, that was a great debate. We did such a great job. But at that time I was talking $2.5 trillion. I guess it’s $5 trillion now. Whatever it is, it’s a lot more.

Okay, so this is what we know about the mysterious figure: Mr. Elegant was present and presumably onstage at a debate during which Trump mentioned the $2.5 trillion figure.

Which debate was it? Hard to say, since Trump dropped his $2.5 trillion-offshore talking point during many of the dozen primary and four general debates. We might be able to narrow it down to just the ones in which Trump performed well — since Trump said he thought the debate was “great” and that he did “a great job.” But that doesn’t help, since Trump’s typically … generous self-evaluations probably aren’t the most reliable metrics.

Mr. Elegant’s identity is particularly hard to pin down, as he could be a primary opponent or a debate moderator. Of Trump’s Republican rivals, few would seem likely candidates for the “elegant” moniker (remember John Kasich’s argyle sweater?), and Trump often used belittling nicknames for them (see Little Marco and Lyin’ Ted). All of which leaves moderators as chief suspects.

Could he be CNBC’s John Harwood? Maybe ABC’s David Muir? Possibly CNN’s famously dapper Anderson Cooper, though Trump didn’t mention the $2.5 trillion directly in the debate that Cooper moderated, per the transcript.

So, absent a Sherlockian solution, we’ll nominate as top possibilities Fox News’s Chris Wallace, who refereed the last faceoff between Trump and Hillary Clinton, and NBC’s Lester Holt, who moderated their first — and in that debate, Trump’s offshore talking point got more play than usual.

Here’s Trump’s sound bite in the debate moderated by Holt:

Republicans and Democrats agree that this should be done, $2.5 trillion. I happen to think it’s double that. It’s probably $5 trillion that we can’t bring into our country, Lester. And with a little leadership, you’d get it in here very quickly, and it could be put to use on the inner cities and lots of other things, and it would be beautiful.

Perhaps we’ll never know who Mr. Elegant is — but it seems the game is afoot.

UPDATE: Mikey Smith, a reporter for the Mirror, appears to have solved the case! He unearthed a Trump tweet from November 2015 in which the then-candidate praises the Wall Street Journal’s Gerard Baker for his debate-moderating performance. “Gerard—wonderful job last night as moderator of the debate,” he wrote. “I told many, ‘really smart and elegant.'”

So in the interview last week,  when Trump said “we did so great in that debate,” he wasn’t using the royal “we” that so many pols employ to credit the work of their aides — he was referring to himself and Baker.