Special counsel Robert S. Mueller III, pictured here in 2013, has never said how long his Russia investigation will last. That doesn’t stop the press from speculating. (Saul Loeb/AFP/Getty Images)

Sooner or later, Robert S. Mueller III will end his investigation of Russian interference in the 2016 election and the potential involvement of President Trump’s campaign. This will be good news for some lucky reporters because it will mean that a few of them will finally be right.

Stories reporting that the special counsel was nearing the end of his investigation have been around for more than a year, which is more than half as long as Mueller has been conducting his investigation. Since then, Mueller has reportedly been “wrapping up” or “winding down” his “probe” dozens of times.

The Hill newspaper reported last week that the end could be near. The Washington Post did the same a week earlier. Last month, it was NPR’s turn. CNN had the story, too, confidently reporting that Mueller’s team “has begun writing its final report,” according to “multiple sources.”

Politico said the end was nigh in October, as did Bloomberg News, as did Fox News. The New York Post said something similar in June. So did Wired the month before, as did . . . oh, just Google it yourself.

So far, no report and no end. Just more probe.

Stories like this have invariably been wrong because they are, at best, guesswork. The people who purport to know when Mueller will complete his work are outside his circle and appear to be mostly within Trump’s, giving everything a gloss of wishful thinking. There are clues about Mueller’s intentions but no authoritative confirmation. Stories of this kind might as well come with an asterisk reading, “*Maybe.”

There’s one guy who knows when Robert S. Mueller III will end his investigation, and he’s not talking. The most obvious, and perhaps most frustrating, thing to reporters about Mueller is his confounded discipline. A Cone of Silence seems to hover over his head as he strides through some hallway, eyes downcast, in that endlessly looped cable-news B-roll footage of him. Mueller doesn’t issue news releases, doesn’t give interviews, doesn’t chat up Don Lemon on the panel at night. He and his team of lawyers — the inaccurately described “17 Angry Democrats” of Trump Twitter fame — are the worst possible sources. Because they aren’t sources at all.

Even the man employed to speak for Mueller doesn’t speak for him much. Peter Carr, who handles Mueller’s press at the Justice Department, seems to be the Maytag Repairman of spokesmen, perpetually idle. Carr rarely tells reporters anything more illuminating than “No comment.” In response to a request for an interview last week, for example, he emailed: “We are declining interview requests, so I’m not going to be able to participate at this time.”

In fact, he hasn’t “participated” at any time, giving no interviews of substance since Mueller began his investigation in May 2017.

It’s this insufficiency of information that may explain why the Mueller-is-wrapping-up-his-investigation genre exists in the first place. Like nature, journalists abhor a vacuum and are eager to fill it. And so they have, again and again, despite missing, again and again.

The vacuum has also been filled by a couple of subgenres about Mueller. One is the kind of story in which Republicans grumble about why Mueller’s investigation is taking so darn long. A common facet of these stories is a contextual paragraph pointing out that, in fact, Mueller really isn’t taking so darn long (choose one: that Ken Starr investigated Bill Clinton for more than four years; or that future Supreme Court justice Brett M. Kavanaugh spent nearly three years failing to prove right-wing conspiracy theories about the suicide of Clinton White House counsel Vince Foster).

The other subgenre is the counter-wrap-up story — the assertion that Mueller’s investigation could go on much longer, despite what you may have read or heard. These stories have actually proved more accurate than the dominant wrapping-up-soon narrative, despite proceeding from the same factual black hole.

All of it raises an obvious question: What’s the point of these predictive stories, anyway? What journalistic purpose is served by trying to guess when Mueller will finish? It will surely be news when he does finish, but for now the guessing game seems only useful if you, personally, were going to be indicted or if you were planning a Mueller wrap-up party.

To be fair, reporters aren’t the only ones who have made bad predictions about when Mueller’s work will conclude. Trump’s legal team has forecast the end many times, too. Slate compiled a list of these predictions from the likes of Rudolph W. Giuliani and others last summer. They start with lawyer Ty Cobb’s statement to Reuters that he’d be “embarrassed if this is still haunting the White House by Thanksgiving and worse if it’s still haunting him by year end.”

That would be the end of last year. Cobb made this statement in August 2017, at which point Mueller was just warming up.

Back then, of course, Cobb was still representing Trump. He quit in May. As of now, he’s one of the few who have actually wrapped anything up.