Catherine Glenelg, Susanna Appleton's sister-in-law and friend, had never had a good relationship with her mother-in-law, Jean Ferguson. But when Catherine returns to consciousness to find herself lying on a staircase landing with Jean's dead body beneath her and no memory of what happened to put her there.... Surely it couldn't be that she had somehow killed Jean?

Subsequent examination of the body shows finger marks on Jean's neck, and Catherine's own cheeks bear scratches indicating a fight, making it clear to those around her what must have happened. It takes little urging from the friend and former spy Catherine had invited to help her recover her son from the Scottish court, where Jean's maneuverings had landed him, to flee without waiting to see if anyone would believe in her innocence. With her memory gone, Catherine isn't sure of it herself, and who up North in Scotland amongst her late husband's family and friends would defend the English Catherine?.

When Susanna hears that her beloved Catherine has been charged with murder and gone missing, she immediately heads north to see what she can do to help. Charging up after her is her horsemaster, Fulke, who had always been a friend of Catherine's and had received a note saying that Catherine's daughter had been sent to him for safety. Problem was, she never arrived.

Susanna is sure that Catherine would not leave Scotland without her son, even to save her own life, but where could she be hiding? Where could her daughter be, assuming she and her nurse hadn't met the likely fate of a pair of females traveling alone? And if Catherine didn't kill her mother-in-law, then who did... and, just as importantly, why?

Thus begins a deadly game of hide-and-go-seek, as various groups of people seek each other out or hide from each other, while some of them are investigating a murder or trying hide their role in one. The game takes them from Edinburgh to Stirling Castle and the court, to some of the more isolated bits of Scotland, all the while with danger and deceit all around them.

This is what historical mysteries are supposed to be: tightly written, fascinating stories that couldn't occur in the same way at any time other than their chosen setting; full of period detail and feel because they're written by someone who clearly knows that setting well, but never beats the reader over the head with that knowledge. Recommended.