It’s December and Durham is bustling with shoppers and visitors, as carollers fill the air with festive cheer – until a chilling murder shatters the peace. Retired teacher Alistair Morley is found dead, sheet music crammed down his throat, while The Coventry Carol plays in the background.

DI Tom Stonem is called and soon thrust into a sinister investigation that reveals Morley was formerly choirmaster at the now-closed St. Bartholomew’s Academy. As the body count rises, each victim is linked to the school and its mysterious past, and the killer’s twisted symphony plays out. When a cold case of a missing chorister also turns out to be far from closed, Tom is torn between uncovering the truth or uncovering secrets that threaten his nearest and dearest., the stakes escalate, and the killer’s final act looms ominously.

As Christmas Eve approaches, Tom must decipher the killer's chilling motives before the clock strikes for midnight mass. Will he unearth the truth behind the hidden messages in the carols – or become the next victim in a deadly performance?