For Nathanial Stone and Annabelle Somerset, the most harrowing journey has only just begun! At long last, Nathanial and Annabelle are back on Earth, but the reception is hardly what they hoped for – Nathanial locked up in Chatham Convict Prison, Annabelle and her uncle Cyrus Grant held in the Tower of London: the charge – treason! Someone high up in the British government is putting pressure on them for mysterious reasons. But when the Austro-Hungarian ambassador to Britain is assassinated in a gunpowder plot which would have made Guy Fawkes smile, events spin out of everyone’s control. The clock is ticking down on the arrival of the new Austrian ambassador, and on an assassination plot which aims to cut the heart out of the British monarchy and government. The race to thwart the conspirators will take Nathanial, Annabelle and George Bedford through the heart of Whitechapel at night, to gunpowder barges anchored in the Thames, to seedy boarding houses attacked by infernal clockwork devices and finally to the dizzy heights of a zeppelin docking gantry packed with explosives and where a single spark will mean extinction for all.

The Heart, a mysterious ancient life form around which the Earth's moon was shaped, contains the secrets of the ages. Secrets it is willing to share with humanity. Only the British Empire is telling no one, not even their allies. In a concealed base, researchers are developing a method to push the Empire beyond the limits of the Asteroid Belt. To succeed, they need certain, previously unknown, minerals and metals. To that end they have assembled a top covert team: Scientific genius, Professor Nathanial Stone; American adventuress, Miss Annabelle Somerset; and the former captain of the Royal Navy's flagship, Jacob Folkard, who is linked telepathically to the Heart. Before the mission can begin, though, they require one more person: French mineralogist extraordinaire, Arnaud Fontaine. Their journey takes them on a detour to Messor Base, a mining instillation on Ceres, the largest body in the Asteroid Belt. Things are not running as smoothly as they appear. People are missing, fresh meat is being served in the canteen... How far will Dylan Blayney, administrator of the base, go to keep the truth hidden? For in the world of Ceres, something has been disturbed, and a great price must be paid.

It all seemed so straightforward at first... Quantity surveying in the rain drenched swamps of Venus. How hard could it be? Endure a bit of rain, dig about where directed and Bob’s your uncle. To be sure, there were the local carnivorous lizards the size of houses, occasionally hostile natives and the local German colony, which had never proved particularly reasonable when it came to servants of the Crown digging about in what they clearly felt was their back garden. But by now, that sort of thing was barely more troublesome than setting out an afternoon tea for the good crew of the Esmeralda II. True, some might call a plan a touch problematic if it requires bailing out of an airship in a single-seat experimental glider while a Venusian storm rages. If said plan also involves landing in German-controlled territory in order to meet a marginally sane geologist named Jungle Ned, one might even call the whole affair tricky. But things go from tricky to worse when they arrive at Ned’s hideout and find it ransacked and covered with indecipherable symbols. Of Ned there is no sign other than a single hidden note: The gods brought themselves down. Before they discover its meaning, our heroes will find there is more to Venus than just peat bogs and hungry fauna. Forgotten secrets linger in the mists. And sometimes what is forgotten is still very much alive…