After 10 years and a public expenditure of $21 million, the longest independent counsel investigation in history has finally come to an end. The anticlimactic result was no charges, no indictment, but a 746-page report speculating without evidence that there might have been a high-level cover-up.

The investigation centered on Henry J. Cisneros, President Bill Clinton’s housing secretary. Mr. Cisneros was accused not of abusing power or misusing public funds but of lying to the FBI in his pre-employment interview about cash payments to a former girlfriend. He agreed in 1999 to plead guilty to a misdemeanor charge and pay a fine of $10,000. Other charges were dropped. The matter appeared to be ended. Mr. Clinton pardoned him before leaving office.

But David M. Barrett, the independent counsel who had been appointed in 1995 to investigate the case, apparently suspected there was more, including a cover-up involving the Justice Department and the Internal Revenue Service. Mr. Barrett kept on for another four years, despite a 2001 letter from the Bush administration’s Justice Department that the expansion of the investigation was unwarranted. The three federal judges who had appointed him in the first place finally called a halt in 2003 and ordered him to end the investigation and write his final report. That took three years more.

The seamy background suggests why the original case fell apart. Mr. Cisneros had quit as mayor of San Antonio after admitting an affair with one of his aides. President Clinton nominated him anyway for secretary of housing. In the FBI interview, Mr. Cisneros said he had paid the former aide $10,000 to start her life over. The appointment was confirmed, but the payments continued, amounting to $71,000 in 1991 alone. The aide had also taped her phone conversations with the secretary, sold them to a tabloid television station and accused him of lying to the FBI. That touched off the investigation.

But Mr. Barrett’s staff found that she had doctored the tapes and indicted her for lying and obstruction of justice. Mr. Barrett brought an 18-count indictment against Mr. Cisneros. With his own chief witness an accused liar, Mr. Barrett had a poor case. He eventually settled for the misdemeanor plea.

In his final report, Mr. Barrett accused the Justice Department and the IRS of blocking his investigation of whether Mr. Cisneros evaded taxes in connection with his affair. But the three-judge oversight panel found the accusation too trivial to be made public.

Congress has wisely let the independent counsel law lapse. There must be some workable method for nonpartisan investigation of suspected official wrongdoing, but this open-ended, expensive, loose cannon mechanism isn’t it.