Instinct follows Dr. Dylan Reinhart, a former CIA operative turned university professor and author who specializes in abnormal behavior. His quiet life is upended when NYPD detective Lizzie Needham recruits him to help catch a serial killer who is using his book as a blueprint for a series of gruesome murders. Despite his desire to stay retired, Dylan finds himself drawn back into the world of espionage and investigation, utilizing his unique psychological insights to solve complex cases. As the series progresses, Dylan and Lizzie form an unlikely but effective partnership, balancing their contrasting methods—Lizzie’s street-smart, procedural approach versus Dylan’s academic and tactical expertise. Together, they navigate the dangerous underbelly of New York City, tackling high-stakes crimes while dealing with the personal complications of their pasts and the ongoing challenges of working within the rigid structures of the NYPD.