Anthony Weiner is behind bars in Massachusetts, serving 21 months after pleading guilty to federal obscenity charges for sexting with a teenage girl. Weiner’s silver Dell laptop, however, refuses to go away.

In October 2016, the discovery that e-mails from Hillary Clinton to Huma Abedin—her chief aide and Weiner’s wife—had been copied to Weiner’s laptop led to then-F.B.I. director James Comey announcing that he was reopening the bureau’s investigation of Clinton’s messaging habits. The new probe found nothing new or incriminating—but its launching may have swung a decisive number of votes to Donald Trump.

After the election, the laptop became central to a theory that anti-Clinton agents in the bureau’s New York office withheld its contents in order to force Comey’s hand. Now the laptop intrigue is back with a vengeance, and this time, it is being used to suggest that the F.B.I.’s leadership was somehow biased in favor of Clinton—and to help justify the ouster of F.B.I. Deputy Director Andrew McCabe.

On Monday, leaks claimed that a forthcoming report by U.S. Inspector General Michael Horowitz will paint an unflattering picture of McCabe’s decisions. On Tuesday, The Washington Post sketched in some additional detail, basically inferring that McCabe dragged his feet on reviewing the Weiner laptop e-mails at the height of the 2016 presidential campaign. But Michael Steinbach, the F.B.I.’s former executive assistant director for national security, who worked on the investigation, dismisses both the pro- and anti-Clinton laptop conspiracy theories. Rather, he says the roughly three weeks that elapsed between the seizing of Weiner’s laptop and Comey’s decision to reopen the investigation were consumed by ordinary law-enforcement bureaucracy.

“The Weiner investigation was opened up based on Weiner’s inappropriate contacts,” Steinbach says. “In the course of that investigation, New York got a warrant and searched the laptop. As soon as they identified some evidence, the head of the New York office, Bill Sweeney, called down and spoke to the deputy director and a few others. I wasn’t at that meeting, but he called me later that day and said, ‘Hey, we’ve got something.’”

After the unexpected discovery of e-mails from Clinton’s State Department domain name on Weiner’s laptop, Justice Department investigators discussed whether a second search warrant was needed to review them.

“At the time, we got the initial information, it was 600,000 bits or streams of information. There was no belief we would be able to review that quantity of information inside of two months, three months,” Steinbach says. “The conspiracy theory may sound good, but in reality, when you know the volume of what we thought we had—which turned out to be wrong—and the likelihood we would find new e-mails that were classified, which would then need to be kicked out to N.S.A. or C.I.A., for the classification review, we thought this would be probably a couple months-long process.”

McCabe was also contending with the then-undisclosed F.B.I. probe into possible contacts between the Trump campaign and Russian operatives, plus a possible inquiry into Clinton Foundation donations. His life became even more complicated on October 24, 2016, when The Wall Street Journal ran a story reporting that the political action committee of Virginia Governor Terry McAuliffe, a longtime Clinton ally, had contributed nearly $500,000 to the state Senate campaign of McCabe’s wife. On October 27, in a 5 a.m. email, McCabe told Comey they needed to meet as soon as possible. Later that morning, he explained that Clinton e-mails had been found on Weiner’s laptop. The next day, Comey notified Congress that he was reopening the investigation. On October 30, the F.B.I. obtained the second search warrant, allowing it to look at the Clinton e-mails on Weiner’s laptop.