Twenty years ago, three boys staggered out of an old building. Missing for a weekend, the boys had no idea where they'd been, but they all shared the same vague memory of a shadowed woodland grove. Now, Simon has returned to the Concrete Grove to see his old friends and unearth painful childhood memories, and things once buried are beginning to claw their way back to the surface.

The hummingbirds are flying again. Nightmares made manifest walk the streets. A dark entity is calling from the shadows, reaching out to three terrified boys who have grown into damaged men. And the past is about to catch up with them all, staining their lives with a darkness they never truly escaped.

Silent Voices is the terrifying follow-up to McMahon's award-winning The Concrete Grove.