This is a guide to releasing the opium to put everyone to sleep at the House of Blossoms in Chapter 3 Dirty Secrets in Thief 2014.
Sabotaging the Opium Pump
To overload the opium in the House of Blossoms Lower Level you need the wire cutters. Take out both girls in front of the opium tank by first taking out the one in front of the pot and then the other.
Go to the upper level and into the door near the opium tank:
Follow the passage around until you get to the back of the opium pump. Use the wire cutters on the box at the back of the opium pump:
Overloading the Opium Pump
Go back to where the girls were and pull the lever next to the opium tank. Now everyone in the House of Blossoms is asleep and you can explore freely.