Sienna lives a quiet life as a freelance writer in a picturesque neighborhood where nothing truly bad ever seems to happen—until she meets Adrian, her charming new neighbor... and therapist.

What begins as routine therapy quickly spirals into obsession, paranoia, and blurred lines between reality and delusion. When one of Sienna's clients vanishes, she becomes convinced Adrian knows more than he's letting on. He's too polished, too perfect—and always one step ahead.

As strange things start happening around her—voices in the walls, missing time, and haunting dreams—Sienna begins to question everything. Her memories. Her sanity. Even her own innocence.

But the deeper she digs, the more dangerous the truth becomes.

Because someone is watching.

And the real illusion... might be Sienna herself.

A gripping psychological thriller with a shocking twist, The Illusion Next Door is perfect for fans of Gone Girl, You, and The Silent Patient.