Zoe had just got up when Mal gave her the letter. She read it as she was munching on the foul tasting protein bar that was their standard breakfast ration. When she was done she wanted to throw it all back up again, but she forced herself not to. It wouldn't help, and food was too precious to go wasting like that.

Her family was dead.

The ink was stained from her sister's tears. Her sister who had left the ship for a few days while they were in port to sit an entrance exam for flight school and had come back to find the whole town killed by Reavers.

There were too many details, Zoe thought. She didn't want to know how many bodies her sister had seen, or what exactly she had found when she got back to the ship. She didn't need to see the words "even little Tommy."  She didn't want to know how the Alliance was trying to hush it up, pretending that something like this could never happen on one of their planets, or how they were refusing to pay an ounce of compensation to the families of the people killed in their supposedly "safe" docks. She didn't want to feel so bad when her sister said "I wish you were here."

That didn't stop her from reading the letter again and again until Mal touched her arm and asked if she was okay.

"Yeah," she said. She tucked the letter into her boot. "Fine."

She didn't pay much attention in the trenches that day; she was just too numb. Finally, when her cheek got burned from a bullet almost missing it, Mal sent her to plant some mines.

Planting mines was something the newbies got to do every once in a while; not quite as dangerous as sitting in the trenches getting shot at, and mind numbingly boring. Plant the mines and active them, be careful not to step on them after, do the same for the next lot, and so on and so forth. Zoe didn't care. She didn't feel like caring about anything much right now.

She was just about to press the button to active her fourth set of mines when she heard a noise.

Someone's foot, crunching on the dry soil.

She grabbed her gun, hid behind a rock, not making a sound.

An Alliance soldier stepped out in front of her. He was young, probably straight out of boot camp, and was holding his gun way too tightly.

Zoe shifted to get a better shot.

He heard her, looked around and spotted her.

She jumped up and hit him over the head with her gun. He went down, bleeding, but struggled to get up and tore the weapon away from her. He punched her. She punched him back.

She knew he couldn't take her. She punched hard anyway. Rage began to surge through her body like adrenaline and compelled her to carry on.

Another punch, his nose was broken, bleeding, punch, screaming now, punch, crying out for mercy, punch, tears, punch, "Please, God!" he said...

Die, Alliance scum.

She put a knee on his chest to hold him down, though it was hardly necessary at this point, and put her hands around his throat.

All

Squeeze.

Your

Squeeze.

Fault.

Squeeze!

"Damn you!" she cried, tears stinging her eyes as the light vanished from his.

She kept punching him long after he was dead, all the pent up anger jumping at this chance to be expressed, until she collapsed, crying.

After what seemed like an eternity she picked herself up and slowly headed back to find Mal.

She felt sick. She could have just shot him; Lord knew she had more than enough ammo. But she had wanted to see the fear in this frightened little boy's eyes as the life drained from his face, drop by drop.

She had killed more men than she could count, but she had never enjoyed it before. She had never done it just out of anger before, either.

It wasn't a nice feeling. It was terrifying, in fact, to think that she was even capable of such a savage act.

Mal realized something was up, but she brushed him aside. She couldn't tell him something like this.

It could never happen again, she realized, through long nights of lying awake in what passed for a bed here, having given up on a good night's sleep weeks ago. She could never let herself become so consumed by anger again.

Which meant that she should never be angry again.

Cold, yes, cynical, yes, annoyed even, yes. But she promised herself she would never again let herself fall prey to such murderous urges. Because if she did it would destroy her, and she would be no better than the Reavers who had butchered her family.

So at Serenity Valley she wasn't angry. She was depressed and dismayed, perhaps, but not angry.

When her sister was raped and murdered by some fed with enough ties to let him get off without so much as a smudge to his reputation, Zoe was cheerless and frustrated. Never angry.

When Wash got taken by Niska and couldn't sleep soundly for weeks after, she was sad. She couldn't let herself be angry.
 

It wasn't until the Reavers took her husband and her children that she went over the edge and became one of them.