Just how did the FBI start its investigation into potential Russian collusion in the 2016 election? The Department of Justice explanation is that George Papadopoulos got too chatty in a bar, and Fusion GPS’ oppo researcher shared his information with his contacts at the FBI. That information led to a surveillance warrant from the FISA court, and the rest is history.

That may not be the rest of the history, however. Amid dueling claims of extortion and obstruction as well as a threat of impeachment against Rod Rosenstein, a potentially different origin story has emerged, Kimberly Strassel reports for the Wall Street Journal. The DoJ has been keeping a lid on a top-secret source at the center of this probe, and Strassel believes it’s a confidential informant placed by the FBI and/or the CIA within the Trump campaign.

In other words … a spy:

The bureau already has some explaining to do. Thanks to the Washington Post’s unnamed law-enforcement leakers, we know Mr. Nunes’s request deals with a “top secret intelligence source” of the FBI and CIA, who is a U.S. citizen and who was involved in the Russia collusion probe. When government agencies refer to sources, they mean people who appear to be average citizens but use their profession or contacts to spy for the agency. Ergo, we might take this to mean that the FBI secretly had a person on the payroll who used his or her non-FBI credentials to interact in some capacity with the Trump campaign. This would amount to spying, and it is hugely disconcerting. It would also be a major escalation from the electronic surveillance we already knew about, which was bad enough. Obama political appointees rampantly “unmasked” Trump campaign officials to monitor their conversations, while the FBI played dirty with its surveillance warrant against Carter Page, failing to tell the Foreign Intelligence Surveillance Court that its supporting information came from the Hillary Clinton campaign. Now we find it may have also been rolling out human intelligence, John Le Carré style, to infiltrate the Trump campaign. Which would lead to another big question for the FBI: When? The bureau has been doggedly sticking with its story that a tip in July 2016 about the drunken ramblings of George Papadopoulos launched its counterintelligence probe. Still, the players in this affair—the FBI, former Director Jim Comey, the Steele dossier authors—have been suspiciously vague on the key moments leading up to that launch date. When precisely was the Steele dossier delivered to the FBI? When precisely did the Papadopoulos information come in? And to the point, when precisely was this human source operating? Because if it was prior to that infamous Papadopoulos tip, then the FBI isn’t being straight. It would mean the bureau was spying on the Trump campaign prior to that moment. And that in turn would mean that the FBI had been spurred to act on the basis of something other than a junior campaign aide’s loose lips.

Strassel goes on to deduce that the “source” has international connections, based on the justifications used by Rosenstein to keep the source secret from Congress. She believes she knows who it is based on her deductions, but has decided not to reveal the name after getting no confirmation from her own sources. Apparently, the exposure of this source’s identity would create lots of headaches for the DoJ, not to mention — of course — for the source him/herself.

Let’s unpack a couple of things, starting with the “spying” allegation. Does “source” exclusively mean someone planted within an organization, or can it mean a member of an organization who decides to inform on it on their own? Strassel assumes the former, but the latter also makes sense. The difference is more than just rhetorical; it’s the difference between planting a spy and reacting to a whistleblower. If the FBI or CIA sent an agent to infiltrate an American political campaign, that would be an unconscionable intrusion into domestic electoral functioning. If, on the other hand, someone who worked on the campaign went to them and passed along information because they felt that serious wrongdoing was afoot, that’s a significantly different situation — still a bit fraught, but not the same thing as spying.

The timing is another point. If this “whistleblower” report came to the FBI after the Papadopoulos incident, it’s not much of an issue at all. If it came before Papadopoulos shot off his mouth in a bar, and/or if the “whistleblower” turns out to be working for the FBI or CIA, then the Papadopoulos explanation has been a deliberate lie. Deliberate lies aren’t much of a problem in counter-intelligence operations, but they do matter in criminal probes, and that would put a very big cloud over Robert Mueller’s special-counsel efforts. It would also put Rosenstein’s efforts to keep that information from Congress in a particularly egregious light.

What are we to believe? Normally, the DoJ would share this information with the congressional committees that have oversight on its operations, which does include the House Intelligence Committee, as well as its Senate counterpart and the judiciary committees in both chambers. As Paul Ryan has said, it is entirely appropriate for Devin Nunes to seek that information as part of the Constitution’s checks and balances and to hold Rosenstein accountable for defying them. It is not “extortion” to use the power of impeachment against executive-branch officials who defy Congress, although it may be unwise if this turns out to be much less than what Nunes suspects.

Strassel wants Donald Trump to declassify everything related to the FBI’s operations regarding the 2016 election, but that shouldn’t be necessary. If Rosenstein doesn’t want to give Nunes and his team access to that information, then the leaders of the other committees should get access to it. They can determine whether Rosenstein is protecting legitimately sensitive information — or whether he’s protecting the FBI and/or CIA from the consequences of violations of the American trust during the election.