Thirteen-year-old Blue Broen is on the hunt for a legendary ship of gold, lost centuries ago when her ancestors sailed to New York. Blue knows her overprotective parents won't approve of her mission to find their family's long-lost fortune, so she keeps it a secret from everyone except her constant companion, Otis, an 80-pound diabetic alert dog. But it's hard to keep things quiet with rival treasure hunters on the loose, and with Blue's reputation as the local poster child for a type 1 diabetes fundraiser.

Blue's quest gets even harder when she's forced to befriend Jules, the brainy but bratty daughter of a vacationing movie star who arrives on the scene and won't leave Blue alone. While Blue initially resents getting stuck with this spoiled seventh-grade stranger, Jules soon proves Blue's not the only one who knows about secrets -- and adventure.

Will Blue unravel a three-hundred-year-old family mystery, learn to stand up for herself, and find the missing treasure? Or is she destined to be nothing more than "diabetes girl" forever?