after climbing up to the ducts, and you start to crawl through the ventilation
system...appox half way through here, start looking UP and you will find a ladder which
takes you up to the next part of the game.

How do I take out the boss at the end of the Brothel Mission? I keep blasting him andc
trying to stay under cover, but it doesn't seem to make a difference,

Killing Ethan is actually quite easy. Once you get into this phase, blast the fire
extinguisher on the left. Move there and stand there. Keep blasting Ethan with the MG
every time he shows up. He'll retreat and return a few seconds later. Just stay there and
keep blasting him until he drops dead. Be sure to keep the MG loaded. Reload when your
ammo drops in the weapon drops below 30. The key here is not to let Ethan too close.
KWAMU.