Lac Adélard is a French novel written by Canadian author François Blais and published in 2019 by La courte échelle.

He grew up in the surrounding area and knew it well, which inspired him to anchor the book's characters Anna and Elijah there in present time, and those of Rose-Marie and Sarah, also there but in the past.

Instead, he relied on his instincts and adjusted his writing to suit the target audience, making the age of the protagonists the differential change between this book and his previous adult novels.

Thirty years later, teenagers Élie and Anna, find Rose-Marie's diary and take a trip to Lac Adélard in an attempt to unravel the mystery of her disappearance.

Marie Fradette writes in Le Devoir, "we constantly feel the author's ease behind the expected seriousness of the story.