The Night's Dawn Trilogy

The Reality Dysfunction and The Neutronium Alchemist chronicled an epic, far-future struggle set in a universe of thrilling complexity. Multiple worlds, alien races, two types of future humanity, and uncountable forms of fascinating future technology make up the universe created by Peter F. Hamilton. The reality dysfunction is a break in the fabric of reality that allows the dead to return to our world, where they possess living bodies. Gradually, it becomes horrifyingly clear that all of humanity is at risk of being taken over by the minds of those long dead. More and more of the dead are stealing the bodies of those still living, grouping together into powerful consortiums led by leaders from history.
Opposing this development is an increasingly desperate Confederation Navy. Joshua Calvert is assigned to chase after Alkad Mzu, who is trying to recover the doomsday weapon that might possibly blast the dead back into oblivion. Mzu is hunted not only by Joshua, but also by various intelligence agencies and the possessed themselves, all of whom are desperate to lay hands on the weapon.
In The Naked God, the Confederation starts to collapse economically and politically as more star systems fall to the possessed. On Earth, Quinn Dexter plots to bring about the Final Night for the human race. Opposing him is Louise Kavanagh, who unknowingly teams up with the universe's most powerful and secretive policeman. In the midst of all this chaos, Joshua Calvert and Syrinx take their ships in search of an alien god which may hold the solution to the current crisis. Unfortunately, it was lost in space ten thousand years ago on the other side of the Orion Nebula, and the Tyrathca, the only ones who might know where it is, aren't telling.