HOUSTON — Twenty-two witnesses. Piles of documents. Hours of audiotapes and videotapes. And lots of memories of allegedly shady discussions with no explicit orders to commit wrongdoing.

Bit by bit, those pieces made up the puzzle of the government's fraud and conspiracy case against former Enron Corp. chiefs Kenneth Lay and Jeffrey Skilling. Prosecutors rested yesterday.

Now it's the defendants' turn.

Both Lay and Skilling have argued publicly that they committed no crimes. But after the defense opens its case on Monday, the pair will make good on promises to make their case to the only people who really matter — eight women and four men on the jury.

Observers looking for an incriminating e-mail, a tape recording of conspirators planning illegal acts or any other obvious smoking gun were disappointed. The government built its case on the recollections of witnesses who said the former corporate titans' optimistic public statements didn't jibe with internal discussions.

Robert Mintz, a former federal prosecutor who has followed the trial, said each prosecution witness is intended to be viewed as part of a whole that when combined paints a "very damning portrait of these two defendants."

But, he said, "This is still a difficult case for prosecutors because there is no 'smoking gun' evidence. There are no bombshells. There's nothing that conclusively ties the defendants to a scheme to defraud the investing public."

The defendants appeared undaunted. "We're looking forward to getting on the stand and getting our case out there — the positive case," Lay said.

"We are anxious to get our story told," said lead Skilling lawyer Daniel Petrocelli.

Prosecutors declined comment, as is customary during a high-profile trial.