It's 1964 in the tiny town of Eastport, Maine, and Billy McCadie is bored to death. She's surrounded by Jell-O salads and dull people with more etiquette than sense, with absolutely no sign of the intrigue or romance that fill the pages of her beloved novel collection. That is, until an engagement ring and cryptic love letter turn up, addressed to 'Gertrude'.

As Billy gets pulled ever-deeper into in a bizarre and stranger-than-fiction mystery that the local police can't begin to handle, and despite sorely lacking Nancy Drew's effortless charm or Miss Marple's social graces, she finds herself with no choice but to put on her detective hat. But as the body count rises and the danger starts to feel ever closer to home, why does it feel like she's much more than just a side character? Is someone trying to mess with her, frame her, or write her out for good? And after so long yearning to be in the action rather than reading it, and with the only man with two brain cells in Eastport within her reach, would it be so terribly unladylike for her to have some fun of her own?