Anna is on the brink of losing it all when she is handed the career opportunity of a lifetime - working as a ghostwriter for charismatic neuroscientist Nate. Nate's work at the mysterious Pain Laboratory could transform millions of lives, but his research is overshadowed by rumours surrounding the shocking death of his wife Eva. As Anna writes Nate's story, she finds herself obsessed with Eva, a former patient of Nate's who was unable to experience pain but found joy in inflicting it. As she strips away the secrets of their toxic marriage she makes a shocking discovery. And writing the truth will have deadly consequences.