After her brush with death, Verity Fitzroy and the children of the Ministry Seven retreat to London, but adventure has a way of finding them. With her Uncle Octavius somewhere out there, Verity is sure the disappearance of children in the fogs of the capital cannot be a coincidence. But when she and the Ministry Seven find traces of the mysterious emerald flame, they will find themselves whisked into the embrace of dark conspiracies, and ancient puzzles.