Set in Rocky Harbor, a fictional fishing village on Massachusetts' Cape Ann, The Blue Bottle tells the story of 13-year-old Charlotte Hale, the granddaughter of an aging lobsterman, who has been sent to stay for the summer with her grandparents after a less-than-successful school year. On the bus ride there, Charlotte meets an eccentric retired teacher who tells her the story of the blue bottle, a local legend that leads her on a high-stakes quest for an ancient glass bottle, reputed to hold within it all the power of the oceans.