Millers are far from perfect. Childish Jake, his neurotic sisters Beck and Ashley, and clueless mother Deborah find themselves under the same roof for the first time in years when their eccentric grandmother Helen dies. They do not yet know what trials they will undergo when Helen's secret inheritance enters their lives - the famous Florence Diamond, a yellow gem that belonged to the Austrian Empire and disappeared a century ago. With no idea how one of the most mysterious diamonds in the world ended up in Helen's bedroom, they begin to explore her past and realize how little they know about the stunning fate of their brave grandmother and the complicated, deeply involved history of their family.