From the internationally bestselling authors of The Wife Between Us comes this electrifying new psychological thriller about truth, lies and deadly obsession . . .

When Jessica signs up for a psychology study conducted by the mysterious Dr Shields, she thinks all she'll have to do is answer a few questions, collect her money and leave. But as the questions grow more and more invasive, she begins to feel as though they know what she's thinking . . . and what she's hiding. As Jessica's paranoia grows, it becomes clear that she can no longer trust what is real in her life, and what is one of Dr Shields's manipulative experiments.

Caught in a web of deceit and jealousy, Jess quickly learns that some obsessions can be deadly. Here's what readers are saying: 'This is a smart, chilling and suspenseful novel that doesn't let you off the hook until the very last page', 'A great read that has me looking over my shoulder and questioning my daily choices and interactions', 'Deceit, jealousy, obsession, paranoia - An Anonymous Girl has this in bucket loads'.