Robert Mueller has operated for 19 months as a law unto himself, reminding us of the awesome and destructive powers of special counsels. About the only possible check on Mueller is a judge who is wise to the tricks of prosecutors and investigators. Good news: That’s what we got this week.

Former national security adviser Mike Flynn a year ago pleaded guilty to one count of lying to the Federal Bureau of Investigation about his conversations with Russia’s ambassador to the U.S. Flynn’s defense team this week filed a sentencing memo to Judge Emmet Sullivan that contained explosive new information about the Flynn-FBI meeting in January 2017.

It was arranged by then-Deputy FBI Director Andrew McCabe, who personally called Mr. Flynn on other business, then suggested he sit down with two agents to clear up the Russia question. McCabe urged Flynn to conduct the interview with no lawyer present -- to make things easier.

The agents (including the infamous Peter Strzok) showed up within two hours. They had already decided not to inform Flynn that they had transcripts of his conversations or give him the standard warning against lying to the FBI. They wanted him “relaxed” and “unguarded.” Former Director James Comey this weekend bragged on MSNBC that he would never have “gotten away” with such a move in a more “organized” administration.

Keep reading Kimberley Strassel's column in the Wall Street Journal.