WATCH: MSNBC's Rachel Maddow reveals how we finally know why Mike Flynn lied

As the Mueller investigation has moved along, names like Roger Stone, Paul Manafort and Michael Cohen have moved to center stage.

On Friday, MSNBC's Rachel Maddow went back to the start of the saga, when Donald Trump staffers like Michael Flynn and his aide K. T. McFarland were the focus of investigation and speculation.

"The big question about Flynn—and this has been raised over and over again by critics of the Mueller investigation—why did Mike Flynn lie about this?" Maddow asked. "There's always been something hard to figure out about the Flynn case... why did Mike Flynn lie about this stuff?"

Flynn was fired from his job as national security adviser after he apparently lied to Vice President Mike Pence about his communication with Russian officials. But this was far from his only lie, Maddow said.

"Mike Flynn also lied about those conversations he had with Russia talking about sanctions," she said. "He lied in public. He lied to reporters. He lied to the FBI. Why were they lying about it? I mean, on its face, they didn't need to. It would make sense that they'd be talking about sanctions to the Russian government conceivably. They're the top two security officials in the National Security Agency for the incoming administration. Obviously there is going to be a change on the policy. It's not that weird. But they lied about it."

Because Flynn and McFarland lied, Maddow said, "they were both compromised by Russia from the very beginning."

"Because, of course, Russia knew the truth, right?" she said. "Russia was on the other end of the phone. They knew that these guys had been having conversations about Russia, right? It wasn't secret from Russia. But it was being kept secret from the American public, the American press, the American Congress, and even the FBI."

At this point, Maddow circled back to the Trump Tower Moscow project, which Cohen and others lied about—and which came to an abrupt halt on the very same day that it was revealed Russian hackers were seeking to influence the election.

"The story about Russian government hackers being exposed for their role in trying to get into our elections—that was the reason they stopped working on the Trump Tower project that day. The secret project they'd been working on for many, many, many months including direct contact with the Kremlin and planned travel to Moscow stopped that day. Why? What was the connection between those two things?" Maddow asked.

"If the big picture Russian dream here is to have their very own president of the U.S.A., if their dream is to compromise an American presidential candidate so that candidate is beholden to them and then install that compromised candidate as president, then the Trump Tower Moscow project which compromises Trump and the election interference campaign [ruins it]," she said. "Install the candidate, and then leverage the candidate to lift sanctions and free Russia to do what it wants. Now, over this past week, we suddenly can see the full plan."

Watch the segments below.