On Monday afternoon, another senior figure abruptly exited the Trudeau government. But, as with the departure last week of former justice minister and attorney-general Jody Wilson-Raybould, principal secretary Gerald Butts’s resignation is a move that is generating far more heat than light.

His leave-taking, like that of Ms. Wilson-Raybould, is related to the allegation, first reported in The Globe and Mail, that senior officials in the Prime Minister’s Office last year put pressure on the then attorney-general to cut a deal with engineering giant SNC-Lavalin to avoid a criminal prosecution. The scandal is now eating the Trudeau government – or, to put it more precisely, the government is being consumed, day after day, by its inability to rebut the allegation of scandal.

Until Monday, it was hard to overstate the power of Mr. Butts. Canadian government is nominally cabinet government, but the Prime Minister’s Office is the unelected quasi-ministry that stands above the elected members. As principal secretary, Mr. Butts was at the peak of that PMO pyramid, and hence at the top of government. A close friend of the PM since their days together at McGill University, he was a driving force behind Mr. Trudeau’s improbable rise from the political fringes to MP, to party leader, to PM.

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Mr. Butts was not only seen as the most powerful person in government and the chief string-puller behind the curtain; he was also believed to be indispensable to the PM, both as a policy wonk and a political strategist. He wasn’t just Mr. Trudeau’s right-hand man, he was understood as his right arm, or even the right half of his body. And now, just months before the election, he’s gone, or at least no longer running the show at the PMO.

Gone, but the issue that provoked his departure remains. As with the resignation of Ms. Wilson-Raybould, the proximate cause of Mr. Butts’s departure is obvious, while the deeper reason is shrouded in dense fog.

The immediate reason for his resignation is that the government is faced with a political crisis that threatens the PM’s popularity, and even his hold over his party. Mr. Butts, the chief political adviser, has been unable to make that political headache go away.

For more than a week, the government has failed to successfully address the SNC-Lavalin allegation, or to respond to it in a way that puts it to rest. If anything, it has made things worse, sending the Prime Minister into the crosshairs of journalists’ questions, day after day, with an incomplete and evolving story.

It was bad enough when Mr. Trudeau’s first response was to insist that he had never “directed" the attorney-general to defer the prosecution. It was a legalistic phrasing that both suggested something amiss without addressing the allegation, which was not that Ms. Wilson-Raybould had been directly ordered, but that she had been put under pressure.

It was worse when, a few days later, the PM pointed to Ms. Wilson-Raybould’s continued presence in cabinet as proof nothing was amiss – and then hours later, she resigned.

In the days since, the government has been parsimonious with information about what happened, or did not happen, on the SNC-Lavalin file. Mr. Butts’s resignation, momentous as it is, doesn’t change the fact that Canadians still don’t know what the Trudeau government did, or did not do, with regard to the SNC-Lavalin prosecution, and whether its actions involved anything legally or ethically problematic.

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The government has been consistent in denying that it did anything wrong, and that is also part of Mr. Butts’s resignation letter. The problem is that it’s impossible for Canadians to make up their minds on whether the government did wrong, when so little is known about what the government did.

As such, Mr. Butts’s resignation may raise questions about the future shape of the Trudeau government, and even, in an election year, its future as the government. It has also, for the first time, revealed hints of Liberal members jockeying for pole position in a post-Trudeau party.

But it doesn’t deliver what psychologists and political advisers alike always aim for: closure. The key player in this drama, Ms. Wilson-Raybould, has yet to speak and to give her side of the story. Until she does, it remains impossible to say whether Mr. Butts’s departure is a sideshow, or something that goes to the very heart of the narrative.