On the one hand and like most royal commissions, it is trying to focus on broad structural questions.
Why are Indigenous women and girls more at risk of violence than their non-Indigenous counterparts? What can be done to improve the situation? What role does systemic racism play?
On the other, it is supposed to provide some form of comfort to real, individual Indigenous families who have lost female relatives and want to know what happened to them.
When Canada's Liberal government set up the inquiry last year, it hoped the commissioners it appointed would somehow be able to do both. The events of the past few weeks demonstrate how difficult that task is.
The inquiry is in chaos. Five senior officials, including one commissioner, have quit. The remaining four commissioners narrowly escaped a motion of censure last week from the influential Assembly of First Nations, which wants the inquiry's terms of reference rewritten.
The inquiry has barely begun to hear oral evidence. It will be hard-pressed to meet its November 2018 deadline for issuing a final report. It will almost certainly exceed its $53.8-million budget.
At root is the fundamental confusion over the inquiry's purpose. Its terms of reference specify that it is to report on "systemic causes of all forms of violence - including sexual violence - against Indigenous women and girls in Canada, including underlying social, economic, cultural, institutional and historical causes."
But they also specify that the inquiry is to recommend "ways to honour and commemorate" the missing and murdered females.
Many of the families of the missing and murdered argue - understandably - that the best way to honour their relatives is to find out what happened to them.
A significant number say they are not satisfied with police explanations.
But as the inquiry notes on its website, under its terms of reference it cannot reopen police investigations.
It can refer what it considers questionable police practices to the "appropriate authorities," but it can't investigate on its own.
As Indigenous Affairs Minister Carolyn Bennett explained last year, this limitation was part of a deliberate effort to prevent the inquiry from deteriorating into a standoff between relatives and police with both sides "lawyering up."
The government's main aim, she said then, was to get to "the root cause of systemic violence."
The relatives can be forgiven for thinking that this is not enough. The root causes of systemic violence against Indigenous women are already well-documented.
The 1996 Royal Commission on Aboriginal Peoples blamed a cycle of despair rooted in a history of broken treaties and cultural demoralization. British Columbia's 2012 Report of the Missing Women Commission of Inquiry singled out "the legacy of colonialism in Canada."
Other reports, both government and non-government, have come up with similar conclusions. And the Liberals expect this one to do the same.
As Patty Hajdu, then status of women minister, put it last year, this inquiry "must also examine how racism and sexism are embedded in the very institutions that are supposed to help and protect women and girls."
All of this may be very well. But what so many of the relatives really want to know, it seems, is what happened to their specific mothers, daughters and aunts - and why police didn't put more effort into trying to answer these questions.
The inquiry does have the authority to look, in general, at how police treat cases of missing and murdered Indigenous women. On Thursday it issued a statement reconfirming its intention to do so.
Will that be enough to satisfy the relatives and keep this shaky, dual-purpose inquiry on an even keel? I'm not sure it will.
Thomas Walkom writes national affairs columns for Toronto Star. His columns are distributed by Torstar Syndication Services.