Mystery-book aficionado Birdie Lindberg has an overactive imagination. Raised in isolation and homeschooled by strict grandparents, she's cultivated a whimsical fantasy life in which she plays the heroic detective and every stranger is a suspect. But her solitary world expands when she takes a job the summer before college, working the graveyard shift at a historic Seattle hotel.
In her new job, Birdie hopes to blossom from introverted dreamer to brave pioneer, and gregarious Daniel Aoki volunteers to be her guide. The hotel's charismatic young van driver shares the same nocturnal shift and patronizes the waterfront Moonlight Diner where she waits for the early morning ferry after work. Daniel also shares her appetite for intrigue, and he's stumbled upon a real-life mystery: a famous reclusive writer—never before seen in public—might be secretly meeting someone at the hotel.
To uncover the writer's puzzling identity, Birdie must come out of her shell . . . discovering that most confounding mystery of all may be her growing feelings for the elusive riddle that is Daniel.