The collected documents from the Manafort trials make it obvious that prosecutors believe that Manafort attempted, on many occasions, to leverage his leadership of the Trump campaign to salvage his disastrous personal finances. What they have described is a state of desperation, but they haven’t fully articulated where, precisely, this desperation led him. While they have led to his imprisonment, they have let linger a long set of important questions about his time at the helm of the Trump campaign.

Who Is Konstantin Kilimnik?

For nearly a decade, Manafort was trailed by a diminutive aide-de-camp, a Ukrainian named Konstantin Kilimnik. In Manafort’s world, foreign names were often truncated to more easily spelled initials, so Kilimnik went by the moniker KK. According to colleagues, Manafort described KK as his “Russian brains.”

Prosecutors have routinely asserted that KK was an “asset” of Russian intelligence—although it’s not exactly clear what they mean by this, or what evidence supports that conclusion. Over time, however, prosecutors have slowly revealed details about KK. They have shown that KK remained in contact with Manafort during the campaign. One meeting appears to have especially fascinated Mueller: On August 2, 2016, Manafort, Rick Gates (his other longtime deputy), and KK met at the Grand Havana Room, a cigar bar in Manhattan. Manafort supplied Kilimnik with a sheaf of the Trump campaign’s internal polling data. (The blogger Marcy Wheeler has pointed to a footnote in a Mueller filing indicating that Manafort and Gates passed 75 pages of polling to KK.) Apparently, the polling was intended for Manafort’s old financial benefactors in Ukraine, the two oligarchs who funded the political party that Manafort represented. Did they actually receive it? (They have denied ever getting the data.) And did KK give anyone else the closely guarded information?

Manafort, Gates, and KK certainly behaved as if they were engaged in nefarious activity. According to Mueller’s team, the troika left the Havana Room separately, through different exits. Andrew Weissmann, one of Mueller’s lawyers, told Berman Jackson that this meeting at the cigar club goes “very much to the heart of what the special counsel’s office is investigating.”

Read: The loud silence of Mueller’s Manafort memo

Getting “Whole” With Oleg Deripaska?

One of Manafort’s most important consulting clients was the Russian aluminum magnate Oleg Deripaska. Earlier in his career, Deripaska was commonly referred to in the media as “Putin’s oligarch.” Manafort advised Deripaska on political matters, but he also became an investment partner with him. In 2007, Deripaska gave Manafort approximately $20 million to manage in a private-equity fund, intended for investment in properties across Ukraine and Russia. According to court documents, Manafort failed to account for what happened to these funds. Deripaska has accused Manafort of stealing them—and has said that Manafort stopped responding to his requests to reach him.