All of Stephen R. Donaldson's books are pretty dark... I started out reading The Chronicles of Thomas Covenant the Unbeliever and was hooked. The 180^o difference of the two worlds, one where he was a pariah and the other where he was the savior was pretty unique. What was interesting about it is how he dealt with it (and sometimes didn't deal with it well).

The Gap Series I thought was darker than the Chronicles. You could not like the main character of the book, but the plots within plots made it a great read. Not for the person who likes the good guys fighting the bad guys and winning, however...

The Illearth War (The Chronicles of Thomas Covenant the Unbeliever, Book 2)

The Wounded Land (The Second Chronicles of Thomas Covenant, Book 1) -

The One Tree (The Second Chronicles of Thomas Covenant, Book 2) -

White Gold Wielder (The Second Chronicles of Thomas Covenant, Book 3) -

The Real Story: The Gap Into Conflict - is a short but intense tale set in a future in which humans travel between the stars using "gap drives," controllable brain implants are punishable by death, and a private company called the United Mining Company runs law enforcement for all of known space. Ensign Morn Hyland lives aboard a police ship with most of her family, chasing down pirates and other illegals who prey on the weak or smuggle goods into forbidden space.

Through a strange turn of events, one particularly nasty perpetrator ends up with Morn as his companion--or at least that's the way it appears to the folks at the space station's bar. Why would a young, strong, beautiful police officer associate with a crusty, murdering pirate? People watch with interest as Morn appears to fall in lust with another racy illegal, Captain Nick Succorso. Morn and Nick must have plotted together to frame Angus and escape together, right? But the real story was quite different. - Amazon.com

Chaos and Order: The Gap into Madness - Punisher is on the run from Billingate Space Station, as well as other predators that follow: UMCP Enforcement Division director Min Donner aboard a crippled Punisher, Nick's archenemy (and slave to the aliens) Sorus Chatelaine aboard Soar, and the mysterious hired gun, Free Lunch. Corrupt cyborg Angus Thermopyle and ruthless Nick Succorso battle for control of the ship and the situation. Their trail leads to Valdor Industrial, where geneticist/engineer Vector Shaheed seeks to redeem himself by manufacturing an antidote to the mutagen used by the alien Amnioni to mutate human beings against their will. Brutalized yet resilient Morn Hyland, her clone/son Davies, tough officer Mikki, Pup, Sib, and the rest continue their suffering and sacrificing.

Meanwhile, back in Earth space, police and politicians battle for power as UMCP director Dios continues his grim revolution against the Dragon. Assassin kazes, political fears, and provocative bills threaten to paralyze the Governing Council for Earth and Space.

Ships battling in space? Laboratory space stations developing antimutagen antidotes against the aliens who seek to conquer humankind by mutation? Outrage, brutality, betrayal, and secrets? Donaldson lays it all out with sharp dialogue, tense scenes, and zippy action. - Amazon.com

This Day All Gods Die: The Gap into Ruin - Tough-as-nails Morn Hyland, pirate-turned-cyborg Angus Thermopyle, and the whole crew from the United Mining Company Police are back in the final book of the Gap series, This Day All Gods Die. The Gap plot has raced through the galaxy at breakneck speeds, and the conclusion is no exception.

Morn, her alien-grown son Davies, geneticist/engineer Vector Sheed, competent Mikka, and her cabin-boy brother Ciro wait aboard Trumpet. Angus lies unconscious, possibly in permanent stasis. Ciro plots to destroy the ship, driven insane by the knowledge that alien mutagens have been shot into him by Nick Succorso's sworn enemy, Sorus Chatelaine. Following nearby, Min Donner, faithful head of the UMCP Executive Division, watches the action and grits her teeth aboard Captain Dolph's battle-fatigued Punisher. Will Morn trust her? Will her voice commands over Angus's programming prevail? Who has survived the strange journey and battles since leaving the Lab? Back at United Mining headquarters, the Dragon and UMCP Chief Warden Dios's strange, twisted duel of manipulation, assassination, and corruption comes to a head when an Amnion warship sets course for Earth... and that's just the first few pages.

Get set for more of the action, betrayal, characterizataion, intrigue, corruption, and adventure you've enjoyed in the previous Gap books. If it has been a few years since you read the last installment, you may have trouble remembering some names and particularly insidious points of plot and government intrigue; you may even be tempted to reread the preceding books. Also troubling is Angus's continual rumination of a couple phrases, including "We've committed a crime against your soul" and "It's got to stop." However, you may be reading so fast you won't notice. - Amazon.com