Riley Sager delivers a twisty psychological thriller that will appeal to readers who enjoy unreliable narrators and atmospheric mysteries set in isolated locations. The story follows Emma Davis, an artist haunted by the disappearance of her three bunkmates at Camp Nightingale fifteen years earlier.

When the camp reopens, Emma returns as a counselor, determined to uncover the truth about what happened to Vivian, Natalie, and Allison. Sager excels at creating a claustrophobic summer camp atmosphere, complete with dense woods, hidden secrets, and the kind of teenage dynamics that can turn toxic.

The dual timeline structure effectively builds tension as Emma's memories of that fateful summer slowly surface alongside present-day dangers. Emma herself is a compelling but frustrating protagonist—her unreliable narration keeps readers guessing, though her tendency to withhold information can feel manipulative rather than mysterious.

The supporting cast, particularly the missing girls who appear in flashbacks, feels somewhat underdeveloped, existing more as plot devices than fully realized characters. Sager's pacing is generally strong, with genuine surprises and red herrings that mostly play fair with readers. The camp setting is vividly rendered, tapping into nostalgic fears about childhood experiences gone wrong.

However, the resolution relies heavily on coincidence and some character motivations feel thin under scrutiny. The book works best as a page-turner rather than a deep psychological study. Fans of domestic thrillers and locked-room mysteries will find plenty to enjoy, especially those who don't mind protagonists who make questionable decisions. Readers seeking complex character development or literary prose should look elsewhere. The book also contains themes of trauma, guilt, and adolescent cruelty that may be triggering for some. Overall, 'The Last Time I Lied' succeeds as an entertaining summer thriller that effectively uses its camp setting, even if it doesn't quite stick the landing on all its ambitious twists.