Special counsel John Durham’s latest indictment is an important step in unraveling what really happened in the long tale of false Russia-collusion allegations against the 2016 Trump presidential campaign. The facts in the indictment add to the evidence that this was from first to last a dirty trick by Hillary Clinton’s campaign—and that the media were its gullible promoters.

Mr. Durham this week indicted Igor Danchenko, a Russian national who worked at the Brookings Institution in Washington and who was the main source for Christopher Steele’s dossier claiming Donald Trump was in secret cahoots with Russia. The FBI interviewed Mr. Danchenko in 2017 as part of its investigation of the dossier, and the indictment claims Mr. Danchenko lied repeatedly, depriving the FBI of crucial information. (Mr. Danchenko’s lawyer has indicated his client will plead not guilty.)