In the following essay, Donnelly explains to Update how a century-old murder led her to write the Carnegie Medal-winning novel, A Northern Light." Note that A Northern Light was published under the name A Gathering Light in Great Britain.

In A Gathering Light, which has won this year's Carnegie Medal, Jennifer Donnelly tells the story of a young girl, Mattie Gokey, who has to choose between her family, struggling to help her widowed father make a backbreaking living farming in the foothills of the Adirondack mountains, and her own dreams of studying literature in New York.

Interwoven is the true story of a young, pregnant woman, Grace Brown, murdered in mysterious circumstances in 1906. The case achieved notoriety at the time. Grace's lover was arrested and tried for the murder on the strength of her letters recovered subsequently.

The story was re-told fictionally in Theodore Dreiser's An American...