Archie Greene and the alchemist's curse

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.