After their unexpected detour to Anglesey, Tabitha and Wolf are looking forward to a relaxing summer in Pembroke.

Now that Wolf has embraced his inheritance of the Pembroke title, he finds himself curious about its history. Tabitha surprises him by arranging a private tour of the Pembroke Castle ruins for what was supposed to be a lovely family day out. As they wander the castle grounds, listening to the stories told by the knowledgeable caretaker, Tabitha and Wolf make the shocking discovery of a dead body.

While there seems to be much local interest in explaining the corpse away as a victim of a freak accident, Tabitha can’t shake the idea that there is something far more sinister at work. As she and Wolf begin to investigate, they get pulled into not just a murder case, but a puzzle that is over seven hundred years old and involves the very first Earl of Pembroke.

Can Tabitha and Wolf uncover a murderer even as they find themselves pitted against shadowy forces, their every move watched and danger lurking where they least expect it?