In the 1580s, a tutor conducting a boring lesson for a local farmer’s son catches sight of the farmer’s eldest daughter, Agnes, through a window. She has a wild and “witchy” reputation because she can see into the future and because she is frequently seen haunting the forest with her kestrel. They fall in love. The tutor is attracted to Agnes’s independence and certainty, while Agnes can see the tutor’s potential to accomplish great things. When Agnes’s stepmother Joan attempts to frustrate their courtship, they take matters into their own hands, beginning a sexual relationship that leaves Agnes pregnant. This forces their families to agree to their marriage.
Agnes moves into town and into her new in-laws, John and Mary’s, house. A keen and adept observer, she quickly gains an understanding of the family dynamics. She also proves herself to be a capable housekeeper. Prompted by a dream of her mother, when the time comes for her to give birth, Agnes sneaks into the woods to deliver Susanna alone. Hours later, her brother Bartholomew correctly interprets the cryptic message Agnes left for her husband and leads the husband to his wife and newborn daughter in the forest.
Within a year, Agnes is pregnant again. But her husband has fallen into a deep melancholy due to John’s attempts to control him. Despite the personal sacrifice, Agnes conspires with Bartholomew to convince John to send her husband to London, where he can try to make his fortune. Shortly before the birth of twins Hamnet and Judith, he writes a letter home describing his growing interest in the world of the theater. Unfortunately, Judith is too frail to survive life in crowded, dirty London; Agnes remains in Stratford with the children while her husband spends time in London, establishing his professional reputation in the theater and making occasional trips home.
Months before the fateful day on which Judith will fall ill, a Venetian glassmaker burns his hand and leaves his apprentice to pack up his glass beads. The apprentice uses rags instead of straw and sand. A cabin boy plays with a monkey in Alexandria, unwittingly carries the plague back to his merchant vessel where it ravages the ship’s crew and cat population. One of the cats dies on the box of glass beads; its fleas nestle into the rags where they wait until Judith opens the package, many weeks later, in Stratford.
Thanks to a series of unfortunate events, Judith contracts the plague in the summer of 1596. On the day she suddenly falls ill, Hamnet searches through his and his grandparents’ houses for help. Unable to find Susanna, Agnes, Mary, or even the apprentice Ned, and unable to get help from John, who’s drunk, Hamnet leaves to try to fetch help from the physician. Frustrated in this attempt too, he returns home and collapses on the bed next to his sister. Susanna and Mary return and begin to prepare dinner, unaware that Judith and Hamnet lie ill in the upstairs bedroom.
When Agnes does come home, she quickly realizes that something is amiss. Hamnet takes her upstairs to Judith, who exhibits the symptoms of bubonic plague: high fever and swollen lymph nodes. He then fetches Susanna, Mary, and his Aunt Eliza. They all work together to nurse Judith, but she grows sicker and sicker. Soon Mary instructs Eliza to write a letter to the twins’ father with the bad news. As the letter begins its journey to London, Hamnet crawls into bed with Judith. Unwilling to face a life without her, he sacrifices himself, trading places with his sister when Death comes for her. Within hours, he has taken his final breath.
The father arrives the following morning, as Agnes sews Hamnet into his burial shroud. Within days of the funeral, he leaves again, afraid that he will be consumed by his—and Agnes’s—grief if he stays. He remains in London for a full year, leaving Agnes and his daughters to struggle through their grief alone. Agnes is so distraught that she becomes unrecognizable to herself and her daughters.
When the husband finally returns, Agnes quickly learns that he is still just as grief-stricken as she is. He buys his family the biggest and finest house in Stratford, where they slowly begin to rebuild their lives. He comes home more frequently. Agnes replants her garden, while Susanna and Judith grow into women.
Then, one day, Joan visits Agnes with the news that her husband has written a new play, named after—and presumably about—Hamnet. Agnes immediately falls into a second period of melancholy, this one deeper than the last. But when a friend asks if she wonders what is in the play, Agnes becomes determined to find out. Accompanied by Bartholomew, she travels to the city, where she stands in the crowd and watches the work of art into which her husband has transformed his grief. And as she stands there, she realizes that she, too, can transcend her son’s loss now that this play has memorialized him forever.