For the past two years, attempting to understand the complexities of the Mueller investigation and President Donald Trump’s ties to Russia has felt like stumbling through a smoke-filled landscape. For every news story that seemed to chart a path forward, a new layer of unanswered questions would cloud the way. The past seven days may have marked the point at which things began to change, when the smoke began to dissipate, if only the tiniest amount.

One of the biggest developments of the past week, Robert Mueller’s Wednesday sentencing memo for former national security adviser Michael Flynn, can be read in a very straightforward way. Despite the insistence of the president and his surrogates, Mueller still has plenty to reveal, and a lot of it will get to the heart of the question of whether any Trump officials colluded with the Russian government in its efforts to interfere with the 2016 election.

Full of redactions, the filing is another reminder that the investigation is looking into something much bigger and far-reaching than it may sometimes seem, especially when we talk about individual indictments and convictions for “process crimes” such as lying to investigators. This is a giant counterintelligence case involving possible election-law violations, money laundering, and who knows what other criminal behaviors.

Flynn started working with Mueller after pleading guilty to lying to the FBI about his interactions, as a member of the Trump transition team, with the Russian ambassador to the United States during the runup to Trump’s inauguration.

As Mueller’s memo lays out, Flynn began helping investigators early and often, giving “substantial” information to not just Mueller’s inquiry into collusion but at least two other Justice Department investigations, one of which we know from the memo is a criminal investigation. The details about the second and third investigations are mostly redacted, but given Mueller’s description of Flynn’s assistance and his recommendation that Flynn not serve time in jail, we can infer that the former three-star general and head of the Defense Intelligence Agency provided very useful information.

As Mueller’s memo lays out, Flynn began helping investigators early and often.

That Flynn is helping with not only Mueller’s immediate probe into team Trump’s interactions with Russians during the campaign but also the two other investigations indicates that the collusion question is tied to something broader.

For more than a year, Mueller’s team and other investigators have been looking into Trump and his associates’ business dealings, in part because they could very plausibly be tied to that issue of collusion. A former U.S. intelligence officer with experience in Eastern Europe told me using such deals to draw in potential assets would be typical Russian intelligence tradecraft: “I do believe this is about business in Russia or in places Russia has influence. That’s how you pull someone in, by making them offers that are harder and harder to refuse. … This is all about trading favors for future Russian spoils.”

Last spring, it was reported that Mueller has been looking into a proposed peace deal between Ukraine and Russia that made its way to Flynn in his role as national security adviser. The proposal was reportedly brought to Flynn’s attention via Trump’s ex-personal attorney Michael Cohen and former Trump business affiliate Felix Sater. That plan, nominally put forward by a Ukrainian lawmaker representing a pro-Russia political movement with reported ties to former Trump campaign chairman Paul Manafort, was skewed heavily in Russia’s favor. The plan called for Ukraine to hold a referendum on whether Crimea should be leased to Russia for 50 to 100 years in exchange for Russian forces leaving eastern Ukraine. The Times further reported that the plan may have also involved the release of compromising material on Ukraine President Petro Poroshenko, who was elected following the 2014 revolution that ousted Ukraine’s pro-Russia President and Manafort client Viktor Yanukovych. The plan’s blatantly pro-Russia tilt along with the involvement of several Americans with connections to Russia raised concerns that the plan had actually come from Moscow. Last week, Mueller revealed that Cohen and Sater were working together during the 2016 presidential campaign to advance Trump’s efforts to develop property in Moscow and that Cohen lied about it to Congress.

Trump’s history here is worth remembering. The president has long wanted to do business in Russia, he has a long history of traveling to the country as a high-profile American, and there have been a large number of people linked to the intelligence services and Mafia buying his and his family members’ real estate properties and working with him.

It can be difficult to separate high-level Russian business dealings from the Russian government. Trump and many of his associates have either made, or tried to make, money in Russia and other former Soviet countries. There is almost always an unofficial price to making significant money in Russia, often in the form of favors that the Kremlin will seek to advance its political agenda. Trump appears to have struggled for years to secure a major deal in Russia, possibly for lack of a political patron, or krysha. By mid-2016 he looked like an increasingly viable candidate for victory in the presidential election. The Kremlin may have begun to eye Trump not only as a candidate who could hurt Hillary Clinton simply by campaigning against her but as a potential U.S. president who could be enticed into doing the Kremlin favors by the prospect of lucrative business deals in the former Soviet Union.

This has always been the major question hanging over Trump’s presidency, and indeed Mueller appears poised to get to the bottom of it.