Here's a FAQ/Walkthrough:
For your own fun, please consider only reading it after you've finished the quest or in case you're stuck somewhere.
First location (Manurhin):
Q: Where's that Sandrine person I need to meet?
A: She's at the place with the most bystanders / witnesses so she won't get attacked.
Q: So I did what Sandrine asked me to do. Now was that already it? What a lame quest!
A: Maybe you should consider giving the stranger a chance to tell his side of the story before you casually kill him.
Q: Deckard isn't at the bar! Now what?
A: If you wait for just a few seconds, you'll notice someone's running towards you.
Q: The enemies are too strong!
A: Sorry, can't help you there. Try wearing some armor and make every shot count.
Q: Where's Deckard?
A: He's being held, wounded, at the bar.
Between third and fourth location:
Q: Sandra isn't anywhere, now what?
A: She's not there. Just check out the Nav point (get very near to the jump point) and you'll be done for this place.
Q: The three enemies are too strong!
A: Reload and hope for some random confed assistance or try and race straight to the jump point and jump out, destroying the enemies isn't a mission objective.
Q: My quest ends here, but I thought there's also a fifth place to go to?
A: You may only go to the fifth location if you've done something the "right" way before. It's a bonus objective.
Q: I've done everything but now I think I'm stuck!
A: If you've recieved the "special item", then the quest is over. However the "quest finished" message will only appear when you take-off the next time. That's because I wanted to give you some time to enjoy yourself and look at that sweet item you got.