Archie's cousin, Thistle, is about to start his apprenticeship at the Museum of Magical Miscellany. But when it comes to his initiation, the firemark that burns into Thistle's hand is a strange one, and Archie and Bramble are given it too. The Golden Circle is the mark of an ancient alchemist's club and when Archie and his cousins learn about a curse that threatens their beloved museum, they have no choice but to start their own alchemist's club, and face the darkest kind of magic.

The fantastic conclusion to the magical Archie Greene series - with plenty of last twists in store Inside the Scriptorium in the Museum of Magical Miscellany, a black flame flickered across an open page. The letters of the spell twisted and distorted in the dark fire until there was nothing left but cinders. Archie and the Alchemist's Club have been rewriting the magical spells contained within books, but someone is drawing on their power for evil purposes. The museum Elders confirm that their worst fears have come true - the Dark Flame is rising, and they can only stop it by uncovering Fabian Grey's prophecy. Archie vows to help - but is he more closer to the prophecy than he knows? And who is behind the mysterious notes for him, labelled F. G, and with the sign of a raven? With traitors at the museum, and dark magic on the rise, it will be up to Archie to uncover his destiny, protect his friends, and save magic as he knows it.