Steps I took:
Discovered Copperlane,
I went to Goose and Fox,
Met Kaenra, agreed to figure out whats up with her fiancé,
Went to his house,
Met fake Purnisc, he attacked, I killed him,
I went upstairs, found real Purnisc,
Told him "don't push your luck" when he told me to not tell Kaenra in exchange for a discout,
Afterwards, hes selling the drugs at 68cp,
I went back to Goose and Fox,
Kaenra is nowhere to be found.
The quest log says the quest is complete, with the last objective being:
"Find Kaenra in Copperlane; [...] I should find Kaenra and tell her what happened. I spoke with Kaenra earlier at the Goose and Fox."
Here's my savegame: http://puu.sh/qctOH/f942f7ad74.savegame