Iain M. Banks - Consider Phlebas (.mobi) ~DJAUZZIEMAN~

The Culture and the Idiran Empire are at war in a galaxy-spanning conflict. Horza, a mercenary capable of altering his appearance at will (a Changer), is assigned the task of retrieving a dispossessed Culture Mind by his Idiran handlers. The Mind, while fleeing attacking Idirans who consider its existence an abomination, has taken refuge on Schar's World, a Planet of the Dead. Planets of the Dead are graveyard worlds left untouched to stand as a monument to their now extinct civilisations and are nominally forbidden to both the Culture and the Idirans, being under the control of godlike incorporeal beings called Dra'Azon. Horza, however, was one of a group of Changers allowed to be on the planet as stewards and witnesses to its devastation. He may be the only person in the Galaxy, and certainly the only one known to the Idirans, who would be allowed to return. On the way to Schar's World he encounters, and joins, a band of mercenaries and pirates, led by Kraiklyn, on their ship, the Clear Air Turbulence. All the while he is doggedly pursued by a Culture Special Circumstances agent, Perosteck Balveda. The Culture also realizes that Horza is the key to getting to Schar's World and retrieving the Mind. Their plan is to place an agent with him and hope that the agent can get to the Mind first and somehow leave with it.
The plot takes many digressions on the way to the denouement. As the book opens, Horza is about to die an extremely unpleasant death after killing and impersonating a member of the gerontocracy on a world not yet part of the Culture. Here he meets Balveda for the first time. He is rescued by the Idirans and given his mission to find the Culture Mind, but the Idiran ship on which he is travelling is soon captured by a Culture ship. Drifting in an escape suit, he is picked up by an independent ship, the Clear Air Turbulence (CAT), crewed by a Free Company of mercenaries, and he has to fight and kill one of them (while still in the form of a very old man) in order to prevent them dumping him back into space.
Horza soon resolves to take over the ship by replacing the Captain, Kraiklyn, who leads them on some disastrous pirate raids which kill several of the crew. The first raid backfires because the team is unaware that the temple they plan to rob has been built of laser-reflecting crystal, which turns their beams back on themselves. The next raid takes place on the Orbital Vavatch, a massive artificial "ringworld" 14 million kilometres in diameter, which the Culture is about to destroy to prevent the Idirans taking it over. The crew lands on an abandoned Megaliner cruising the Vavatch ocean, hoping to salvage its powerful laser weapons before the Orbital is destroyed, but one of the crew is killed soon after landing because he missed the briefing warning them that their antigravity devices would not work there, and more die when the ship crashes into a massive ice wall, which Kraiklyn had mistaken for a cloud bank, although Horza later discovers that Kraiklyn and several others managed to escape.
Horza flees the disaster in the damaged CAT shuttle, but it crashes into the sea near an isolated island, killing the pilot. There he is taken prisoner by a bizarre cult, led by a monstrously obese homicidal cannibal, whose followers subsist on food that has been prepared in such a way as to remove almost all nutritive value and mixed with excrement. Horza escapes his impending sacrifice by killing the cult leader and his henchman with his poisoned fingernails and teeth, and eventually makes his way to the main city on Vavatch to find Kraiklyn. Having now changed his appearance to mimic that of the CAT captain, Horza witnesses a game of "Damage", which Kraiklyn has joined in the hopes of winning enough to make up the losses from his foolhardy expeditions with the crew. Damage is a card game enhanced with psychological and emotional pressure by direct mind-to-mind contact, where the "tokens" of play are actual living beings who are killed when a player loses a round. The game is illegal and only played in places where the normal order is breaking down, as in the case of Vavatch, which is being evacuated.
Kraiklyn is wiped out of the game, and Horza then follows him on his way back to his ship, kills him and returns to the CAT. There, to his dismay, he is introduced to the newest crew member - although disguised, he immediately recognises her as Perosteck Balveda. Just as Horza immobilises her with a stun gun, Culture agents outside try to capture the ship. Horza manages to lift off and takes the Clear Air Turbulence on a wild ride through the massive spaces of the ex-Culture GSV which is carrying out the evacuation, and they escape into space after shaking off their Culture pursuers, although a Culture drone, Unaha-Closp, is also trapped on the escaping ship and becomes a reluctant member of the team. As the fugitives warp away from Vavatch, they see the Orbital destroyed by the Culture warships. Balveda, now exposed as a Culture agent, in turn exposes Horza; seeing no reason to continue his deception, he instead recruits the remnants of the crew to carry out his mission.
Horza and his crew land on Schar's World and go in search for the Mind in the labyrinthine Command System, a vast subterranean complex built as a nuclear warfare command centre (ultimately, though, it was germ warfare which wiped out all life on the Planet of the Dead). They soon discover that the Mind is also being hunted by a pair of Idiran soldiers, survivors of a larger commando group, who have killed all the Changers stationed on the planet, and who regard Horza and his crew as enemies, having no knowledge of the Changers' alliance with the Idirans. Horza has kept Balveda alive, possibly as a hostage, and she goes along with the mission, awaiting her chance to swing the outcome in the Culture's favour. Horza's situation is further complicated when his crewmate Yalson reveals that she is pregnant to him.
The Free Company encounter the Idirans in one of the Command System stations but after an intense firefight, they apparently kill one and manage to capture the other. After tracking the Mind to another station, the drone Unaha-Closp discovers it hiding in the reactor car of a Command System train, but while the team are distracted, the captured Idiran, Xoxarle, frees himself, kills the guard and sets an ambush for the others. Meanwhile, the second Idiran, who had been mortally wounded but not killed, has managed to set one of the trains for a collision course. As the runaway train smashes into the station, Xoxarle springs his ambush, and Yalson is killed. The enraged Horza pursues Xoxarle, who catches Balveda and breaks her arm to slow Horza down. In the climactic fight, Horza is overwhelmed, but thanks to the combined action of the drone and Balveda, Xoxarle is finally killed. Although the Mind has been rescued the cost has been terrible - all the crew of the Clear Air Turbulence have been killed, the drone is severely damaged, and the fatally wounded Horza dies soon after Balveda gets him back to the surface.
Following the final chapter, an appendix tells of the continued lives of the surviving characters, and a summary of the causes and course of the Culture-Idiran war.