Thief in the Castle (Stars and Bones, #1)

The notorious Juniper Thimble is destined for execution. Caught stealing the king’s crown—in addition to her long list of crimes—she has only one way out. Juniper must survive the biggest, most deadly con of her life, commissioned by the king himself. Disguised as the crown prince’s lover, she is forced to protect him with her life…literally. Guarded by a surly squire, relentlessly attacked by demons, and surrounded by mysteriously disappearing servants, Juniper must dispatch the threat to the prince’s life before they find out who she really is.