In the continuing Casteel saga, Annie Stonewall, an aspiring artist, and Luke Casteel, both now 18 years old, have not only grown up legally as first cousins, but knowingly as half-siblings with that connection being Annie's father, Logan Stonewall, and arguably most importantly best friends in Winnerow, West Virginia. Following her parents' deaths in an accident that also paralyzes her, she meets her step-great-grandfather Tony Tatterton, whom she knew of but her mother Heaven refused to discuss in their estrangement, and he invites her to live with him at Farthinggale Manor in Boston, where she can recuperate under the care of a private nurse he has hired, Miss Broadfield. Annie accepts, craving to know more about her mother's family and Farthinggale, with which she has always been fascinated (too much so for Heaven's liking) and be closer geographically to Luke, who will be attending college in Boston. At Farthinggale, Annie like she's being held prisoner by delusional Tony and tyrannical Nurse Broadfield; the only other person she is allowed to have contact with is her ambitious Uncle Drake Casteel (Heaven's half-brother), who now works for Tony as a Regional Manager. If Annie is able to get out from under their control, she might discover ties to her true past, especially what is hiding behind the forbidden garden maze on the Farthinggale property.
—Huggo