Important areas
Passageway A – One of the two available passageways to the second part of the underground. Choosing this path is only available if you've used the ventilation shaft and it will allow you to avoid two guards.
Passageway B – One of the two available passageways to the second part of the underground. Choosing this path means using the stairs. You may be forced to avoid two guards (main passageway) or you can try avoiding them (side passageway).
Starting point - passageway A – You will begin the exploration of the second part of the underground here if you've chosen passageway A in the past.
Starting point - passageway B – You will begin the exploration of the second part of the underground here if you've chosen passageway B in the past.