The congressional investigation into the Ukraine scandal has largely skipped over Giuliani’s efforts—which means that investigators have yet to delve into Dmytro Firtash’s possible involvement. But now that Parnas has added a fresh layer of detail to the narrative, some basic questions should attract attention:

IS IT POSSIBLE THAT THE PLOT AGAINST BIDEN BEGAN WITH FIRTASH? According to the Daily Beast, Firtash has long seethed at Joe Biden. As vice president, Biden vigorously promoted an anti-corruption agenda that included liberating Ukraine’s energy sector from Firtash’s dominance. In fact, when Biden visited Kyiv in 2015 and spoke before Parliament, he seemed to praise the Ukrainian government for “closing the space for corrupt middlemen who rip off the Ukrainian people.” Firtash raged against this speech. He described Biden as an “overlord.” He said, “I was ashamed to look at this. I was repulsed.” If Firtash promised Parnas material that could be used against Biden, he was fulfilling a long-held grudge.

Most narratives of the plot against Biden allege that corrupt Prosecutor General Viktor Shokin concocted the whole scenario out of a desire for vengeance. Biden, after all, had demanded that the Ukrainian president fire Shokin, whose office was a bastion of corruption. (Oligarchs notoriously pay handsomely for the allegiance of prosecutors, who bring cases against their enemies.) Over time, it has become clear that Shokin and Firtash are allies. In September 2018, at the request of Firtash’s lawyers, Shokin filed an affidavit in Austrian court testifying to the oligarch’s innocence. How long have Shokin and Firtash been allies? Were they working together when the plot against Biden first germinated?

WHAT HAPPENED AT NAFTOGAZ? Parnas and Igor Fruman hoped to obtain a contract to export American natural gas to Ukraine. As part of this scheme, they seem to have launched a campaign to remove the leadership of the Ukrainian national company, Naftogaz, and to install managers more favorably inclined to their bid. Given the complexities of putting together a bid, it’s puzzling that they would have focused so heavily on Naftogaz, especially since other details of the plan were so distant from realization.

Is it possible they were fixated on remaking Naftogaz because of Firtash’s long-running battle with the company’s reformist leadership? Firtash believes that the company owes him money and that it is unfairly preventing him from accessing stored gas that he believes he owns. Was Parnas’s team attempting a coup at Naftogaz on behalf of Firtash?

WHAT DID GIULIANI DO ON FIRTASH’S BEHALF? Giuliani has consistently sought to minimize his ties to Firtash. But over time, he’s conceded that he spoke with the oligarch’s lawyers in Chicago and that he met with his proxies in Europe. Did Giuliani press Firtash’s case at the Justice Department? That is, did he fulfill the quid pro quo that Parnas alleged this week? Did he attempt to help Firtash avoid American justice in exchange for material on Biden? In October, The New York Times reported that Giuliani had met with officials in the Justice Department to discuss the case of a foreigner accused of bribery. Giuliani wouldn’t name his client, whom he described as “very, very sensitive.” Parnas told Rachel Maddow that he overheard Giuliani discussing his Ukrainian operation with Attorney General William Barr. If they in fact took place, did those discussions ever include the subject of Dmytro Firtash?