Toward the end of her new memoir, “Both/And: A Life in Many Worlds,” Huma Abedin recalls what she said to her estranged husband, the former Democratic Representative Anthony Weiner, when the F.B.I. seized his laptop less than two weeks before the 2016 presidential election.

“‘Anthony,’ I said, wanting to shake him through the phone, ‘if she loses this election, it will be because of you and me,’” she writes.

The “she” was Hillary Clinton, and Abedin had worked for her when she was the first lady, a senator, the secretary of state, a contender for the Democratic presidential ticket and finally the Democratic nominee. As Clinton neared the end of her presidential run, however, Abedin’s marriage imploded. In a series of catastrophes befitting a Greek tragedy, her husband’s illicit text messages to a 15-year-old girl sparked an inquiry that led the F.B.I. director James Comey to reopen an investigation into Clinton’s emails.

Abedin had been harmed by Weiner’s behavior before. But this time, looking back on the humiliating collision of her personal and professional lives, Abedin writes, “This man was going to ruin me, and now he was going to jeopardize HRC’s chances of winning the presidency, which would leave our country in the hands of someone dangerously unfit for office.”

“Both/And” comes out on Tuesday. Here are seven takeaways from the book.

Abedin arrived in ‘Hillaryland’ during a marital low for the Clintons.

On Aug. 17, 1998, the same day former president Bill Clinton denied his relationship with Monica Lewinsky before a grand jury, Abedin entered the White House residence for the first time.

“Looking back, I can almost mark the milestones of my professional development alongside the breaking news developments in the Starr investigation,” she writes. Abedin recalls Hillary Clinton appearing to be “a little tired looking” but “otherwise seemingly unperturbed by the testimony happening simultaneously two floors below.”

An unnamed senator forced himself on Abedin.

When Clinton was in her first term as a Democratic senator from New York, a male senator invited Abedin over for coffee. “Once inside, he told me to make myself comfortable on the couch. I watched him take off his blazer and roll up his white shirt sleeves,” she writes. “It was like any other day on the Hill.”

Then, “in an instant it all changed. He plopped down to my right, put his left arm around my shoulder, and kissed me, pushing his tongue into my mouth, pressing me back on the sofa. I was so utterly shocked, I pushed him away. All I wanted was for the last ten seconds to be erased. He seemed genuinely surprised that I was rebuffing him and immediately apologized that he had ‘misread’ me all this time.” She doesn’t identify him in the book.

Abedin saw the first questionable email to Weiner in 2009.

She and Weiner were engaged at the time, visiting the Dominican Republic with the Clintons on New Year’s Eve. Abedin suggested they call their families to wish them a happy New Year, and when he asked her to call his parents, she picked up his BlackBerry.

“I noticed an unread email from a woman whose name I did not recognize,” she recalls. “I felt a hot rush of blood from my head down to my fingertips. The message was fawning, flirtatious and very familiar, as though this was a woman Anthony knew.” When she asked him about it, “he said, in an entirely composed manner, ‘Oh, that’s nothing. Just a fan.’”

“I didn’t know a seed was being planted in his psyche that would grow into something much darker and uncontrollable, something that would ruin us,” Abedin writes. “I was in the midst of what I believed to be a deep, true love affair. Nothing in my experience could possibly have prepared me for what was to come.”

She was enraged by his lewd behavior. He called it a game.

In May 2011, Weiner posted an explicit picture of himself on Twitter, then deleted it, claiming his account had been hacked. A week later, he admitted to Abedin — and to the public — that he intended to send the photo to a woman he’d “befriended,” and that “it had been a tawdry joke, a dare.”

Abedin recalls feeling “strangled” by fury. “Anthony’s explanations were never long and never satisfactory,” she writes. “It was all a virtual game, he said, he would tune in, play with other avatars and then return to reality.”

When Weiner went to a treatment center in Texas, Abedin recalls thinking it was “overkill.” Did he really need a long-term therapy plan? She was sure this behavior was “a weird blip, something I didn’t understand but that he had put behind him. And despite everything, the rage, the shame, the ache in my heart, I knew I still loved him.”

Weiner’s sexting continued, and each revelation of his adultery was more poorly timed than the last.

Two days after the 2012 terrorist attack in Benghazi, Abedin glanced at Weiner’s computer and spotted another “playful” message from a woman. “What I mainly felt then was anger at , this stranger flirting with someone who had lost his entire career for having inappropriate online relationships with strangers,” Abedin writes. “Maybe it should have been a warning that he simply couldn’t stop falling into certain behavior but I was overwhelmed with work and worry, devastated by what had happened in Libya.”

In 2013, when Weiner was running for New York City mayor, a woman went public with the “inappropriate exchanges” they had shared. To the chagrin of her mother and Clinton, Abedin agreed to speak on his behalf before the press. “We were all so far down into the minute details of my personal life, I no longer knew what belonged to me and what did not,” she writes. Abedin reached her breaking point six weeks later, when Weiner repeatedly requested her company at a less-than-celebratory election night party where the woman who had leaked the chats promised to appear.

She writes, “I had given up trying to understand or decode Anthony’s mental health.” Abedin expected Clinton to request her resignation; instead, Clinton said that “she did not believe I should pay a professional price for what was ultimately my husband’s mistake, not mine.”

Abedin hit her limit when their child appeared in one of Weiner’s sexts.

“I wish I could take back the image that appeared but I can never erase it,” Abedin writes of a picture that surfaced in August 2016. “There was Jordan, sleeping peacefully next to an indecent Anthony, an image shared with a stranger, or a ‘friend’ in Anthony’s view.” She continues, “This crossed into another level of degradation, a violation of the innocence of our child. There were no more ‘what were you thinking?’ questions left in me. It was over.”

Children’s Services interviewed Abedin’s son and told her that she had been named “in a report of suspected child abuse or maltreatment.” The investigation continued for months, as new allegations surfaced against Weiner (this time involving a teenage girl, “a new nadir”); as Abedin learned that Weiner had been diagnosed with sex addiction; through his stint in a residential treatment program (price tag: $127,000); the seizure of his laptop; and finally the 2016 presidential election.

In January 2017, Abedin received a lengthy report concluding that she was capable of caring for her son. “HRC had lost the election,” she writes. “My consolation prize was that I would be allowed to keep my child.”

For a time, she blamed herself for Clinton’s defeat. Now she blames Comey.

Abedin and Weiner separated in 2016 and later divorced. She was haunted by her husband’s actions, the F.B.I. investigation and how they may have contributed to Donald Trump’s victory. “For a long time, Comey was a daily nightmare for me, and even now the thought of what he did sometimes creeps in to torture me,” Abedin writes. “But I have slowly come to accept that I am not the sole cause of the 2016 election loss.”

She holds Comey, the F.B.I. director, responsible. “One man’s decision to play God forever changed the course of history,” she writes. “It should not be my burden to carry the rest of my life. It should be his.”