Received from: automatically after arriving on the surface of planet Illium [Illium - Nos Astra]
Description: This quest will appear in your personal journal after you've landed on the surface of planet Illium (Crescent Nebula > Tasale) and started exploring an area called [Illium - Nos Astra]. Completing the first part of this quest is required if you plan on completing two other main missions - Dossier: The Justicar and Dossier: The Assassin. Start off by talking to the Concierge and you'll find out that Liara T'Soni wishes to speak to you.
Finding Liara is going to be very easy - all you have to do is to use the stairs leading to the administration office. Talk to the receptionist Nyxeris (first screenshot) and then head inside. During your conversation with Liara you can focus on talking about your former relationship or you can get down to business. Liara will ask you to find and hack a couple of security terminals for her. Don't forget that if you agree to help her you'll gain renegade points and you'll receive even more of them if you continue working together. If you wish to focus only on other primary missions ask her about potential crew members from Dossier: The Justicar and Dossier: The Assassin quests.
There are three security terminals for you to hack and you can find all of them in the southern section of [Illium - Nos Astra] (area near the rapid transport station and several stores). Each time you've found an interactive security terminal (first screenshot) you'll have to solve a mini-game and then locate a corresponding terminal (second screenshot) within 60 seconds. You can use sounds and numbers seen on the screen to guide you to the second terminal from each pair (lower values mean that you're getting closer).
You shouldn't have any problems with all three trials, because one minute is more than enough time to complete each part of this assignment. Finding the second terminal from the last pair should result in Liara asking you to return to her. Go to the administration office again and learn more about her problem. Liara will inform you that she will need some time to figure out the next step and the best solution would be to return to her after completing another mission. For now you can only claim a reward - 2000 credits.
After you've returned to Liara to learn more about her problem she will ask you to hack into several other terminals, this time in hopes of identifying who the Observer is. You can agree to help her right away or you can try convincing her to change her mind. Sadly the only two solutions are to help her or not. This time you'll have to inspect five terminals and you'll find all of them in the northern section of [Illium - Nos Astra].
You can start finding the terminals in any order you like, however if you want to understand all the messages properly you should follow my instructions. The first terminal is to the north-west of the parquet (first screenshot). Naturally you'll have to solve a mini-game here, but this time you won't have to race against time. All you have to do is to read a message left on the terminal. If you want to end this quest quickly you can contact Liara right now, however I would strongly recommend finding four remaining terminals.
The second terminal can be found inside the Eternity bar (first screenshot), near the Bartender. The third terminal is in the eastern section of the parquet (second screenshot).
The fourth terminal can be found in the western section of the parquet (first screenshot). The final fifth terminal is located near the stairs leading to Liara's office (second screenshot). You can contact Liara right now.
This quest can have one of two endings. If you wish to lie to Liara you can choose one of five suspects to be the Observer and if you want to tell her the truth you must inform her that none of the suspects matches the evidence you've collected. Liara will figure out on her own that the person she was looking for is in fact her assistant Nyxeris. Either way, after you've informed Liara about the results of your investigation you must return to her office. If you've assisted her in catching the real Observer you'll receive 5000 credits. Otherwise you won't get any rewards.