England, March 1643

While the civil war between King Charles and his Parliament continues to tear the nation apart, erstwhile lawyer, Gideon Lennox, returns to England as part of a royal escort and in the employ of Sir Philip Lord, a mercenary commander with a mysterious past.

Accompanied by Gideon and Daniel Bristow – Lord’s second in command who has his own history to confront in London – Lord risks a journey behind enemy lines to Mortlake.

They discover the house that once belonged to the alchemist John Dee has become a tapestry works.

Before they can begin to investigate any secrets the property might hold, they learn two of the weavers have taken their own lives within a few days of each other and in the same locked room.

Gideon sets out to find the truth behind the deaths. In the process, he and Lord discover many carefully concealed secrets.

But they are not the only ones in search of those secrets. Gideon is confronted by an old adversary and the full force of the mysterious organisation known as the Covenant is unleashed against them.

Trapped in the alchemist’s house, Gideon has to fight or die.