Dark Obsession by P.J. Fox

When the young and lovely Charlotte Dane arrives at Wrest Park, she’s unprepared for what she finds. She’s been hired as a nanny to the ten-year-old heir of a vast fortune. But inside the dark, forbidding mansion hide greater mysteries than what might have happened to his mother. There is her charge’s uncle, a man who seems to be the epitome of charm and whose confinement to a wheelchair after a terrible accident seems little hindrance. There is his wife, who seems carved from ice. There is his brother, who’s often seen digging in the yard. And then there is his son, her charge’s cousin.

Thorn March is both dynamic and arrogant, a man who drives himself and his many cars with equally reckless abandon. Charlotte learns quickly that he seems to possess every room he enters-and every person in it. But even as she finds herself irresistibly attracted to him, she has to wonder if he truly is who, and what, he appears. Because, inescapably, she’s also forced to conclude that someone wants her young charge dead.

Someone in this family.
Is it Thorn? He’s handsome, sardonic, and dark. From the first she senses some perverted twist to his nature. He’s an enigma, and a compelling one; but is he a murderer, as well?