The Neutronium Alchemist is a science fiction novel by British writer Peter F. Hamilton, the second book in The Night's Dawn Trilogy.
They are able to cross back over into this universe and possess the living, gaining tremendous strength, agility and the ability to create and alter matter.
The Kulu Kingdom colony world of Ombey is also infiltrated and a veteran of the Lalonde fiasco, Ralph Hiltch, is drafted in to help contain the menace.
At the end of The Reality Dysfunction the truth of the nature of the threat is discovered by several survivors of a botched attempt to rescue the situation on Lalonde.
Dr. Alkad Mzu, creator of the feared 'Alchemist' weapon of mass destruction, has escaped from Tranquillity and apparently seeks revenge on Omuta, the world that destroyed her own home planet of Garissa thirty years earlier.
Whilst medical assistance and trauma counselling begin to help heal Syrinx, the information from Laton and the events on Atlantis is transmitted to the Jovian Consensus.
As they become aware of the scale of the crisis, the Edenists immediately switch their economy to a war footing, rendering Jupiter space impregnable to attack.
The Kiint ambassador reveals that, many thousands of years ago, they also suffered a 'possession crisis', as the secret of death is one that is eventually discovered by all sentient races.
Louise Kavanagh's father, Grant, is possessed and gives up his home estate to forces loyal to Quinn Dexter.
After this, with her parents declared missing, Louise takes control of the Kavanagh fortune and is able to use this to book passage on a starship fleeing the system for Earth.
They end up on a ship owned by SII (Mars' national company) and eventually reach High York, an asteroid in the O'Neill Halo in orbit above Earth.
Princess Kirsten authorises the use of lethal force and, in a move which establishes a precedent across the Confederation, the planet's own strategic defence platforms are turned against the possessed, destroying an aircraft and several buses carrying them.
Hiltch visits Kulu itself and is shocked to learn that there was an outbreak of possession in Nova Kong, the capital, but it was put down hard by the authorities.
King Alastair agrees to authorise an alliance with the Edenists, who will provide bitek soldiers to help retake Mortonridge.
Before he departs, Father Horst Elwes relates to him a story about how he was able to 'exorcise' a possessing spirit on Lalonde and tells Joshua to have faith.
The interstellar superstar Jezebelle (a singer and 'mood-fantasy' artist) is on the planet at the time and she rapidly becomes Capone's lover, but also proves to be a valuable source of intelligence on the Confederation.
First Admiral Samual Aleksandrovich learns that the Organisation's next conquest will be the planet Toi Hoi and develops a plan to intercept and destroy their fleet there.
Kiera, the leader of the possessed on Valisk (and the possessor of Marie Skibbow), travels to New California and is able to secure an alliance with the Organisation.
The resulting blast of energy ends the threat of the possessed but also rips Valisk out of the material universe and into a strange realm of grey mists.
On Ayachuko asteroid, in the Dorados, he is shocked to discover that he has a half-brother, Liol, the result of a liaison between Joshua's father Marcus and a local woman nearly thirty years ago.
Joshua and his companions survive thanks to the intervention of a man with strange abilities named Dick Keaton, and are able to extract Mzu safely, although they also have to pick up Monica and Samual.
He abandons his comrades, slips into the ghost realm to evade security, and reappears in the space elevator descending towards the planet.
Safely aboard Joshua's ship Mzu explains how thirty years ago she and other Garrisan starships were on a mission to deploy the Alchemist when they were ambushed and left for dead by Omutan hired blackhawks (as portrayed in the first chapter of The Reality Dysfunction).
Finding himself greatly outmaneuvered, Joshua pulls off a daring stunt by deploying the Alchemist into a nearby gas giant causing it to go nova, destroying the two Organization ships.
Joshua meanwhile uses his ship's anti-matter drive to safely accelerate away from the nova at forty-two gees to a distance where they can make a proper ZTT jump.