It's 1949, post-war Britain and Colonel Longley Walsh lies sprawled at the foot of his staircase.
A dagger protrudes from his chest, and thirty pieces of silver are by his side.
Newly appointed Constable Septimus Plant is called to the scene, igniting a macabre curiosity about the case.
But Septimus has secrets of his own-a brutal mother and a timid father who took his own life. Yet, from an early age, Septimus understands there is power within his silence, complementing his ability to observe and listen-great attributes for any budding detective.
As Septimus studies the art of body language, improving his powers of deduction and combining that with his dogged determination, he sets his wits against a network of perilous suspects.
No one is above suspicion.