Star Wars: The Emperor's Hand.

Chapter one:

Mara Jade was in an unknown place, lurking in the shadows as she always was. That came naturally to her, one of the many benefits of being trained on stealth at a young age was that you had a lot of time to perfect and memorize the best techniques not to be noticed. She just stood there, watching the Emperor on his throne as he looked at the stars. Then all of a sudden Vader appeared, but not alone, he was accompanied by a blonde hair boy with blue eyes. After that everything got foggy, she didn't understand what exactly what was going on, but she heard screams and lightning then screams again. A then a feeling, a horrible feeling, that she thought she would never come across, a feeling of emptiness. Just like that, the Emperor's presence disappeared, she couldn't see nor feel him, anywhere, he was gone.

Then she woke up in her room at the Imperial palace. The feeling of emptiness was replaced by anger and relief it was nothing more than a nightmare. A nightmare that she was having quite frequently, but one that would never come true, the Emperor's reign got stronger every day that passed, and together with it, anyone who decided to oppose his rule was quickly silenced. Vader would also never defy the Emperor, he was much afraid of him to do so. Mara shut down that thought, she had more important things to do than spend her time trying to justify her delusions, today she would be assigned a new mission.

What exactly was it about she did not know, but for Palpatine to assign the mission for her, it must be something of great importance. The Inquisitors, strength had been in question since the Fortress Inquisitors disaster, but Mara has been able to come on top of that, and show that she's no incompetent like the Second Sister or Darth Vader, and the Emperor would take notice of that, and maybe promote her, or even let her take Vader's place at his side.