Greg Pak 
Firefly: Return to the Earth That Was Vol. 3 [PDF ebook] 

Can the Serenity crew finally take care of the Alliance once and for all?What happens when your worst enemy becomes your only ally? With her sights set on freeing Leonard, Kaylee’s team chases the Jefa across the Earth That Was only to be led directly into a trap. But everything changes when they get attacked by plunderer robos who have been tracking both groups… to exterminate them all. Now, Kaylee must team up with the Jefa in order to fend off the robos. But if they survive this, how will they survive each other?Meanwhile, Kaylee faces the grim choices… and sacrifices involved in saving the Earth That Was. Which of the crew will follow their Captain, ready to make peace with the past and face what future the ‘Verse holds for them? And if our heroes can take care of the Alliance once and for all, what destiny will the Washbot choose?Collects Firefly #33-36.