Excerpt from In Extremis by Lindsey Hilsum, plus links to reviews, author biography & more

The sea was a constant in the Colvins' lives, just a bicycle ride away. In winter, when the bay froze at the edges, they would drift out on ice floes, daring one another to go out farther. In the summer, they would spend the whole day at the beach. They joined the Scouts and went camping at Planting Fields, a nearby park and arboretum, green and lush in the summer, sparkling with orange, red, and gold by October. The leader of Marie's troop noticed that at the end of a hike, Marie would frequently be on her own rather than sticking close to the others. "She was not naughty, only curious and unafraid," she noted later. "Her dominant, courageous personality stood out even then."

The center of Oyster Bay comprised a handful of shops, a railway station, the municipal buildings, and that was about it. The loudest noise came from the gulls that lifted and hovered over the ocean. It was a safe place, one where everyone knew everyone and children wandered freely, but nevertheless, the dangers of the world beyond Long Island hung over them. The elementary school Marie attended held periodic nuclear drills, in which the children were told to gather in the hallway, where there were no windows, and crouch against the walls. (How this was meant to save them in the event of nuclear war was unclear.) One day in November 1963, Marie arrived early to take Billy and Michael home from kindergarten, about a mile from the house. "I didn't know what it was, but I could see that something horrible had happened," Michael recalls. "She was crying so I started crying, too, as we walked." The teacher had broken the news to Marie's class: President Kennedy had been assassinated.

For Bill and Rosemarie it wasn't just a question of remembering where they were when they heard the news. As mainstays of the local Democratic Party, they had campaigned tirelessly for Kennedy. When he came to office in 1961, the Democrats, who had previously been the underdogs, gained control of the Oyster Bay Town Council, a sign of the new liberal mood sweeping America. Local politics gave Marie her first glimpse of power and corruption. Oyster Bay was a Republican bastion, the Grand Old Party in Nassau County reputed to be the most powerful in the country. The party chairman, Joseph Margiotta, drove a car with the license plate "GOP-1." Municipal hiring, promotions, and contracts all went through him, and he was eventually convicted of collaborating in an insurance scheme to benefit his political cronies.

In 1965 a newly elected Democratic town supervisor sacked the town historian and appointed the "young and dynamic" Bill Colvin. Marie's father did the job, unpaid and part-time, for a year until he was appointed to a full-time salaried position as county treasurer that required him to take a leave of absence from teaching. When he ran for election within the party, the kids were dragooned into making buttons in red, white, and blue with the slogan "Count on Colvin." When he was defeated, his loyal eldest daughter declared it "a conspiracy." In the evenings, after the children tumbled into the house, conversation round the dinner table frequently turned to politics. Marie heard her parents lamenting America's deepening involvement in the Vietnam War. She saw their despair when Robert Kennedy and Martin Luther King Jr. were also assassinated, and understood their disappointment when, in 1968, the Republican Richard Nixon was elected.

* * *

By 1969, Marie was attending Oyster Bay High, a public school in an imposing 1920s art deco building, its russet brick walls decorated with white limestone friezes above sash windows, just a hundred yards from the bay. Excelling in both arts and science, she went straight into the honors class. Sometimes her home scientific experiments went awry, such as when she tried to incubate a duck egg by making a cradle out of a towel she hung on a standard lamp in her room. That night, at around 1:00 a.m., the towel caught fire. Smelling smoke, Rosemarie rushed up to gather the children and take them onto the patio as the firefighters arrived and the neighbors gathered to watch the drama. Marie had just started to keep a diary, in which she recorded her verdict: "DUMB!"

Excerpted from In Extremis by Lindsey Hilsum. Copyright © 2018 by Lindsey Hilsum. Excerpted by permission of Farrar, Straus & Giroux. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.