Massachusetts, 1954. With bags packed alongside her heavy heart, Alice Campbell escaped halfway across the country and found herself in front of a derelict building tucked among the cobblestone streets of Cambridge. She turns it into the enchanting bookshop of her dreams, knowing firsthand the power of books to comfort the brokenhearted. The Cambridge Bookshop soon becomes a haven for Tess, Caroline, Evie, and Merritt, who are all navigating the struggles of being newly independent college women in a world that seems to want to keep them in the kitchen.

When costume designer Ariana Ricci leaves her groom at the altar, she seeks solace with her great-aunt, a Texas-born Hollywood legend who worked on the film Roman Holiday as an extra. There, Ariana discovers Audrey Hepburn gave Ruby Raines an intriguing necklace during filming, and a cache of 1950s letters, postmarked Italy, raises more questions about Ruby’s hidden past.

Ava and Joseph Simon reluctantly put their nine-year-old son, Henry, and four-year-old daughter, Catherine, in the care of their son’s teacher, who will escort them on a boat to mainland England. Just as the ferry is about to leave, the teacher’s sister Lily appears. The two trade places: Helen doesn’t want to leave Guernsey, and Lily is desperate for a fresh start.

Accordion Crimes opens in 1890 in Sicily as an accordion maker completes his finest instrument and dreams of owning a music store in America. He and his 11-year-old son, carrying little more than the accordion, voyage to the teeming, violent port of New Orleans. Within a year, the accordion maker is murdered by an anti-Italian lynching mob, but his instrument carries Proulx's story as it falls into the hands of various immigrants who carry it from Iowa to Texas, from Maine to Louisiana, looking for a decent life.

The ornate reading room at the Boston Public Library is quiet—until the tranquility is shattered by a woman's terrified scream. Security guards take charge immediately, instructing everyone inside to stay put until the threat is identified and contained. While they wait for the all-clear, four strangers, who'd happened to sit at the same table, pass the time in conversation, and friendships are struck. Each has his or her own reasons for being in the reading room that morning—it just happens that one is a murderer.