Following the disastrous retreat of the British army from Dunkirk in 1940, England is plunged into a state of fear. The threat of a German invasion is real, and many German Nationals are interned in camps across the country. One such camp is on the ancient moor land of Prees Heath, near the small town of Whitchurch in Shropshire, where Tom Tyler is the sole detective inspector. Young women from all walks of life have joined the Land Army, to help desperate farmers keep the country fed. Then one turns up dead.

In the cold Toronto winter of 1895, the naked body of a servant girl is found frozen in a deserted laneway. The young victim was pregnant when she died. Detective William Murdoch soon discovers that many of those connected with the girl's life have secrets to hide. Was her death on attempt to cover up a scandal in one of the city's influential families?

Christine Morris has been sent to Edinburgh to attend a conference on the latest in police methodology. There she is tracked down by the Northern Constabulary, Stornoway, Outer Hebrides, who inform her that her estranged mother has been involved in a vehicular homicide and has gone missing. Reluctantly, Christine agrees to fly up to Stornoway, where her mother was last seen. Her arrival is followed by the suspicious death of one of the islanders.

December 1899. After the death of her beloved grandmother, Cleopatra Fox moves into the luxury hotel owned by her estranged uncle in the hopes of putting hardship and loneliness behind her. But the poisoning of a guest on Christmas eve throws her new life, and the hotel, into chaos. Cleo quickly realizes no one can be trusted, not Scotland Yard and especially not the hotel’s charming assistant manager.

On a cold winter morning in 1873, a crowd gathers on the shore of a Nova Scotia fishing village. A stormy sea has thrown a ship onto the rocks. The villagers work bravely to save the ship's crew. But many die. When young Will Murdoch and the local priest examine the bodies, they discover gold and diamonds. They suspect that the shipwreck was not responsible for all of the deaths. With the priest's help, Will - who grows up to be a famous detective - solves his first mystery.