I love Timothy Zahn's Star Wars work and Mara Jade was an inspired entry into the Star Wars universe. Despite that, we haven't seen too many good Mara Jade stories. Even the Mara Jade-centric novel Allegiance failed to give Mara much depth. Fortunately, I found "By the Emperor's Hand" on eBay for a cheap price and got to enjoy some real Mara Jade adventures.
In "By the Emperor's Hand", Mara Jade is tasked with taking out Black Nebula, a criminal organization like Black Sun. This adventure on its own is fun. However, what made this story worth reading - and what almost all Mara Jade stories since the Thrawn Trilogy have lacked - is character growth. This comic covers the period from the beginning of ROTJ to after the Emperor' death. We see Mara cope with the repercussions of Palpatine's death, as well as the repercussions of her own actions. Mara's sense of justice and righteousness come through as her mission against Black Nebula becomes personal. There's a particularly great scene in a cantina that perfectly encapsulates the character.
As much as I like the book, it's clear Timothy Zahn isn't a natural at writing comics. The story spends far too much time with Mara's thoughts, especially during the first third of the book. It would have been better had it focused more on dialogue or visual images. Still, this is well worth the read for Mara Jade fans.