Obsidian Alliances
Obsidian Alliances is a Star Trek: Mirror Universe anthology – the second book in the series – written by , Keith R.A. DeCandido, and Peter David. Published by Pocket Books, it was first released in trade paperback in .

Summary 
From the book jacket
Some say the line between good and evil is narrower than we imagine – a divide as subtle as a mirror, and perhaps just as deep. To peer into its black, reflective glass is to know the dark potential we each possess, and we cross that obsidian boundary at our peril… into a world where we no longer recognize who we are or what we believed ourselves capable of.In the late twenty-fourth century, decades after the fall of the once-mighty Terran Empire, the Klingon-Cardassian Alliance dominates the worlds that, in another reality, made up the United Federation of Planets. Humanity and its former subject races are now bound together by their shared oppression, slaves to their cruel and brutal conquerors. But a downtrodden few have found the courage and the strength of will to act. Inspired by visitors from another continuum to fight for their freedom, they have rekindled hope… and rediscovered an ancient truth: that every revolution begins with a vision.

 A rebel ship commanded by a former slave named Chakotay attempts to evade pursuit in the Badlands… only to encounter a strange ship that was catapulted seventy thousand light-years across the galaxy. On board the craft are two aliens, one of whom has the potential to completely alter the balance of power within the Alliance. But as both sides of the struggle race to get to the stranger first, treachery throws all schemes into a tailspin.Star Trek: New Frontier Following the Terran Empire's collapse, its longtime rival, the Romulan Star Empire, has absorbed many of the fringe civilizations spread across that part of the galaxy. One of the Romulans' slaves is M'k'nzy of Calhoun, a savage and unpredictable Xenexian who dreams of death… and who learns the value of freedom from the unlikeliest of teachers, a Romulan named Soleta.

 One fallen dictator's struggle to regain her power and her position leads to the discovery of a bold rebel plan for a decisive military strike against the Alliance. But while  navigates the dangerous road of politics, sex, and military intrigue that she believes will lead her back to reclaiming the Intendancy, cracks form in the rebel leadership, leading to a showdown that will change the course of the Mirror Universe.

 "Saturn's Children"  Written by Sarah Shaw (David Mack). "The Mirror-Scaled Serpent"  Written by Keith R.A. DeCandido.Chakotay and  are members of the Terran Rebellion, and while running from an Alliance ship in the Badlands encounter Neelix and Kes, who have been swept across the galaxy to the Alpha Quadrant. The Alliance then tries to find them, with hopes to use Kes's telepathic abilities to their advantage. One of the most powerful and intimidating members of the rebellion: Harry Kim.

 "Cutting Ties"  Written by Peter David. Background information 
 The stories in this collection rely solely on the events of the mirror universe episodes, and do not take into account any previous novels or other spin-off material.
 The DS9 segment ties into the events of the  novels Warpath, Fearful Symmetry, and The Soul Key.
  is thanked in the  for "The Mirror-Scaled Serpent" as a reference source.
 Sarah Shaw is a pseudonym of David Mack. Due to a mix-up in the Pocket Books editorial department, Mack had been contracted to provide two stories in the Star Trek: Mirror Universe anthology collections. Since the offers could not be rescinded, the editors requested that Mack write one of the stories under a pseudonym, which he himself derived – Shaw. Mack noted that working under the pseudonym "freed me up, in a sense, to approach Saturn's Children with a different style. I wrote it much more quickly than I normally do, and by imagining I was a different author I ended up working from a different mindset. It was an intriguing experience." 
 Different versions of the mirror Janeway, the mirror Torres, and the mirror Annika Hansen previously appeared in Dark Passions, Book Two.
 In The Mirror-Scaled Serpent'', it is mentioned that  was the slave of the mirror universe version of T'Kar for many years. This was an in-joke based on the fact that both characters were played by Tim Russ.
 Cover art by Tom Hallman, design by Alan Dingman.

Characters 
  Leader of Terok Nor
  Mirror counterpart of B'Elanna Torres; half-Klingon, half-
  Mirror counterpart of Mackenzie Calhoun; a Xenexian slave of the Romulans

References 
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Anthologies