Bar Tab

Bar Tab is an optional side quest and achievement in Deus Ex: Human Revolution. It is given to the player by Bobby Bao, the barman in The Hive nightclub in Hengsha.

Introduction
After you have gained access to the basement or talked to Tong Si Hung, a bouncer by the door on the way out will recommend you speak to Bobby. You can also approach Bobby directly.

Overview
Bobby needs help locating one of Tong's clients and convincing her to pay what she owes. To find her, you must first disable three communication relays (Level 2 hacking required) located near and around Hengsha Court Gardens area. After you've done so, your HUD will display Jaya's location. She is in Hengsha Court, in an apartment is on the top floor, just down the hall from the room where you searched for Arie van Bruggen in the Hunting the Hacker mission.

Once you find her, speak to her. She will refuse to pay you, but you have several options (in order to receive the reward, a Praxis Kit from Bobby, do not take Jaya's implant). Return the credits to Bobby to receive the Praxis Kit and finish the mission. If you took her implant, Bobby won't give you the reward. However, You can take the Praxis Kit and/or any paid credits from Bobby at any time by knocking him out (details below), but this will fail the mission.
 * Offer to pay off her debt. Return to Bobby, where he will demand 5,000 credits. Pay him to finish the mission, and you will receive the reward and the Guardian Angel achievement.
 * Use the Social Enhancer and choose Alpha to convince her to pay you 250 credits. Note: You can also convince her to return her implant, but if you do so, Bobby will not give you the Praxis kit because he is angry that  you ended a lucrative business arrangement . In Director's Cut, if you return the chip Bobby will still tell you off, but you complete the quest for 1000 XP (You do not get the Praxis Kit).
 * Knock her out and take only her 400 credits. Again, if you take her implant Bobby won't give you the Praxis Kit.