Sixth-grader Hero Netherfield knows she’s in trouble when, on her first day at her new school in Maryland, a classmate unthinkingly announces that Hero is her dog’s name. Despite the inevitable humiliations that ensue, things look up for Hero when she discovers that her family (including her beautiful older sister Beatrice, graphic-designer mom and Shakespeare-obsessed dad) has moved into the “Murphy Diamond House,” where a centuries-old, million-dollar diamond might be hidden. Mrs. Roth, the kindly next-door neighbor, plies Hero with cinnamon toast and tantalizing information about said diamond, and they become fast friends with each other . . . and, interestingly, with the cutest, most popular boy in the eighth grade, Danny Cordova. The plot thickens as Mrs. Roth reveals that she is in possession of the Elizabethan necklace that once held the missing Murphy diamond, an artifact that may even help illuminate the much-debated identity of Shakespeare himself. More linear and traditionally evidence-driven than Blue Balliett’s Chasing Vermeer (2004), this agreeable history-mystery may have even more appeal to budding sleuths. (author’s note, historical timeline) (Fiction. 9-12)