Night Lies

Night Lies, Sharp Little Pinpricks, and Pier Pressure make up the unnamed Cleaning up the Streets collection of side quests.

Acquisition
After defeating several waves of Guardsman Pretender enemies in Hightown at night you will receive the following message that initiates this quest.

The Shallowguard use guardsmen uniforms to get close to their victims. Assault their storehouse, and take out the false captain.

Walkthrough
Enter The "Barracks" and defeat the Guardsman Pretender and "Captain" Qerth". Afterward, return to The Hanged Man and speak to A Friend for your reward.

Result
Defeating "Captain" Qerth" and his Shallowguard troops gives you Palvo's Cocksure Cleaver, Formari Work Boots and other minor loot.

Rewards
2 Sovereigns and 500 XP.

Bugs
It's been reported (but not confirmed) that some people were unable to complete this quest after beginning Isabella's side quests.