The Weight of Water simultaneously follows the story of a real-life murder in late 1800s New Hampshire and Jean, a photojournalist who is doing a story on the murders. Shreve bounces back and forth between Jean’s present-tense narrative of her journey to the island of Smuttynose where the murders took place, and a letter written by Maren, the sole survivor of the brutal killings, on the eve of her death in 1899.