Spies, secrets and suspicious circumstances: Friar-sleuth Brother Athelstan races against time to solve impossible crimes and uncover a traitor in this gripping historical mystery set in medieval London.

London. March, 1382. Deep in the shadows, a clandestine organization known as the Secret Chancery operates under the sinister leadership of John of Gaunt's Master of Secrets. When two clerks from this covert group meet their demise in suspicious circumstances, friar-sleuth Brother Athelstan is urgently summoned to unravel the truth behind their deaths.

A puzzling question lies at the heart of the investigation: how did the killer manage to navigate a labyrinth of locked doors, leaving no trace behind? As Brother Athelstan delves deeper into the mystery, a terrifying threat also emerges: the possibility of treason. King Richard's spies in France are also dying, almost as if someone's discovered exactly who they are . . .

Brother Athelstan must race against the clock to uncover the truth before he and his companions get tangled up in the hunt for the traitor, with fatal consequences for them all.