During the conversation in the pub choose whatever option you want to - it doesn't matter. Then follow Matt (exit door) and talk to him. For ending the prologue you unlock an achievement 'Day 1'.
If you want to unlock another two achievements, open your inventory (by move mouse scroll wheel or move down the cursor) and activate the hint system (bookmark with magnifying glass). You'll unlock the achievement 'Chicken'. If you click the button 'kill kitty' twenty times, you'll unlock the achievement 'Cat murderer'. You need to know that there is also an achievement for not using hint system so is worth to activate the hint system in final part of the game (and save it first). Then if you make through the final part twice, you can get all 3 achievements connected with hint system.
In Randal's apartment go to the living room and open the door to hallway. After not very friendly chat with the landlord try to talk with Mortimer - Randal's flatmate (just click on the door of Mortimer's room).
Take a broom from the living room (near the bookcase). In the bathroom (the middle door) you will find a duck-hanger.
Go to Randal's bedroom and leave the flat by using fire escape. Go down. In the inventory use broom with the duck-hanger, you will receive an extendible duck-hanger and a wire. Use the hanger with the hook and go downstairs.