Fifteen years is a very long time to be burdened by a deep, dark secret. Emma Davis—artist, New Yorker, and first-time art gallery exhibitor—knows that feeling. Emma has been coping with an unresolved trauma from her childhood for her entire adult life. Emma is guilty about something terrible that she did fifteen years ago, and the memory is somehow tied to the three girls that she obsessively paints into each of her works before entirely covering them up with earth, foliage, and other scenery.

The story starts strong: a New York gallery opening, a seemingly coincidental meeting with an acquaintance from the past, and the first hints of a past tragedy involving three teenage girls who went missing at Camp Nightingale, a summer camp for girls. When Emma is given the chance to return to Camp Nightingale as a painting instructor, she accepts, motivated by the opportunity to find closure and a release from her inner demons.

The flow of information then slows to a trickle as Emma begins ending each chapter quantifying how horrible that thing she did was without actually talking about that thing she did. It will take two-thirds more of The Last Time I Lied before the reader can fully understand why she feels so guilty.

The Last Time I Lied gets mileage out of some genre savviness on the reader’s part: the missing girls, the lakeside camp (jokingly referred to as “Crystal Lake” by a character early on), the secretive proprietress, and the old mansion on the campgrounds—The Lodge—that the campers are forbidden to enter. The prose does not really go out of its way to paint the sinister undercurrent that flows through Camp Nightingale, but that undercurrent manages to make itself known all the same.

Emma’s maddeningly slow reveal can be frustrating, but the different threads that make up the plot remain interesting during the middle act: the central mystery is always the fate of the three missing girls from Emma’s past, but other side mysteries are introduced along the way. The camp and the land on which it’s built seems to hold some dark secrets of its own, and Emma’s companions at the camp—both counselor and camper alike—are not very forthcoming with what they know either. The Last Time I Lied is billed as a thriller, but mystery fans will get a lot of enjoyment out of analyzing the relationships between the many clues as they are revealed. At many points, the book reads like a grown-up version of a Nancy Drew mystery.

The final act is kicked off when Emma finally talks about That Terrible Night in full, and it’s like finally going over the apex of a slow rollercoaster climb. The plot twists and revelations come flying, and among the predictable outcomes and the red herrings are some genuine surprises—at least one of which will surely fall under gut-punch territory.

The Last Time I Lied is a well-crafted mystery. It’s also a fine psychological thriller, although it cannot count among the genre’s best. Some of the slower parts in the middle may annoy readers, but the final steep metaphorical drop at the end is one worth experiencing. Mystery lovers will find a lot to like here.