The Poyson Garden — Karen Harper

The letter came in secret, with a pearl eardrop from an aunt long thought dead, resurrecting the forbidden past. Banished by her spiteful half sister, Queen Mary, to Hatfield House in the English countryside, twenty-five-year-old Princess Elizabeth cannot refuse the summons. The Boleyns are in grave danger. And Elizabeth, daughter of Anne Boleyn, is marked for death by a master poisoner whose reign of terror may have royal sanction.

With her few loyal retainers, Elizabeth escapes to Kent. Here, in her ancestral Hever Castle, now held by the Queen's loyalists, Elizabeth seeks to unravel the plot against her. And here, in the embrace of intrigue and betrayal, the princess must find a brilliant, powerfully connected killer -- before the killer finds her....