– Top 5 Globe & Mail bestseller
– Starred review in Publishers Weekly
– Best in month picks by BookRiot, BookBub, Cosmopolitan, PureWow, Criminal Element 

Twenty years ago, eleven-year-olds Charlie Paige and Scott Ashby were murdered in the city of Bristol, their bodies dumped near a dog racing track. A man was convicted of the brutal crime, but decades later, questions still linger.

For his whole life, filmmaker Cody Swift has been haunted by the deaths of his childhood best friends. The loose ends of the police investigation consume him so much that he decides to return to Bristol in search of answers. Hoping to uncover new evidence, and to encourage those who may be keeping long-buried secrets to speak up, Cody starts a podcast to record his findings. But there are many people who don’t want the case—along with old wounds—reopened so many years after the tragedy, especially Charlie’s mother, Jess, who decides to take matters into her own hands.

When a long-dead body is found in the same location the boys were left decades before, the disturbing discovery launches another murder investigation. Now Detective John Fletcher, the investigator on the original case, must reopen his dusty files and decide if the two murders are linked. With his career in jeopardy, the clock is ticking and lives are at risk…

Reviews

Exceptional thriller...Ms Macmillan is one heck of a writer.

Tom Nolan, Wall Street Journal

A brilliantly clever ending caps this riveting thriller. Macmillan remains a writer to watch.

Publishers Weekly (starred review)

Gilly Macmillan digs in deep and gets right to the heart of her characters in this rich and engrossing novel. Vivid, smart, and propulsive, I KNOW YOU KNOW [is a] thoroughly immersive thriller of the first order.

Lisa Unger, New York Times bestselling author

Very highly recommended...the writing and presentation is pitch perfect in this complicated, gripping mystery.

LibraryThing

Fletcher’s down-to-earth policing, combined with his strong sleuthing smarts, creates a compelling flashback-and-present-day mystery, but equally engaging is a secondary character, Charlie's mother, Jess. She wasn’t there for her son, but her self-recrimination and eventual redemption over the course of the case make for compelling drama. Fans of British mysteries or of cold-case procedurals are the natural audience for this strongly written outing by the author of What She Knew (2016), but it may also appeal to devotees of the many true-crime podcasts out there today, including West Cork.

Booklist

[An] original, chilling and twisty mystery.

Criminal Element

A captivating read.

The Sun Times (Owen Sound)