The Railway Detective is summoned by his boss Tallis to journey to Shrewsbury and investigate. If it is a simple case of suicide, Colbeck believes that he may be back home that same evening and no need to trouble his sergeant. But when he reaches Shrewsbury, one mystery is solved. The stationmaster tells Colbeck that the dead man is a director of the Great Western Railway company and he was due to takeover as Chairman. Colbeck wonders if this was a case of murder rather than suicide ...