Slave Hunt

Slave Hunt refers to an unmarked quest in Fallout 3.

Detailed walkthrough
When talking to Mei Wong in Rivet City, you can find out she is an escaped slave and therefore scared of Sister, a slaver who is hunting a rogue android. While Mei's fears are unfounded and Sister isn't particularly interested to learn she's a former slave, it's still possible to make her overreact and kill herself.

You have a couple of options (other than ignoring the situation entirely):
 * Mesmerize Mei and enslave her again. Rivet City will turn hostile, and you receive bad Karma.
 * Tell Sister that Mei is an escaped slave and let her know you told him. She commits suicide and you receive bad Karma.
 * Provide Mei with 25 caps, allowing her to purchase a pistol to defend herself. You receive +100 Karma and the location of the Temple of the Union.
 * Kill Sister. Rivet City will turn hostile (including Mei), but you do not lose Karma. Coming back after Rivet City calms down earns the ire of the guards in dialogue, but thanks from Mei.
 * Mesmerize Sister and he will have a violent reaction to it and begin randomly shooting the place up. Rivet City Security will rush to the scene and kill Sister. Nobody turns hostile.

Bugs
Mei Wong may not actually buy a pistol after you give her the money. You could rectify this by reverse pickpocketing a pistol and ammunition to her.