Okay, the upside of this side quest is that it's pretty simple if you know where to look for the clues and you get a cool 50,000¥ in your bank account for accomplishing the task. The downside is that you have to go against some serious Matrix systems and you'll probably spend most, if not all of the 50 grand just getting your deck and its programs up to the point where they can take on the corp systems. So, if you want to do this, I hope you're doing it for the glory and the congratulatory note in your notebook, because you don't stand to gain much, materially speaking.
As mentioned in the previous part, the order of steps 1 through 5 is arbitrary and you can tackle them in any order that's convenient. The systems are pretty equal in terms of challenge, except perhaps for the Ares system whose linear path filled with Tar ice can be very tough to wade through.
As for your deck, you need to be running high-end versions (at least Level 5) of Attack and Deception on a deck with good Masking and in general, a high MPCP. You don't necessarily need to be running a Fairlight Excalibur, but I would advise against trying to take on these systems with the old Allegiance Alpha, no matter how good your decker is.
And speaking of deckers, a Computer rating of at LEAST 6 or 7 is a must. Make sure also that your decker has good ratings in each of his or her Attributes, especially Combat. When you feel you've got a pretty strong setup, you can go ahead and start hunting for the clues.
Where to start? Well, you need to have access to each system. You could keep trying random systems with the System Search option, but that would take entirely too long. Your best bet is to visit Caleb Brightmore and keep asking him for jobs. He gives out a fair share of expert matrix runs and most of these will be against the systems of the corps involved in this quest. Remember that as soon as you accept a job, the system passcode is stored in your deck if it's a named system. Remember also that there is no penalty whatsoever for backing out of a run. With these things in mind, your best strategy is to keep asking for jobs until you are offered a Matrix run against one of the corps. When this happens, take the job and immediately cancel it (or go through with it, doesn't matter). The corp's passcode will be stored on your deck and you'll be able to visit the system whenever you want. Repeat this process until you have the codes for all the systems you need stored in your deck. Then all you have to do is get to a terminal and run through each system, picking out the clues.
So, assuming now that you know how to get into the systems, the following steps will deal with what to do once you're inside:
Get the clue from the Aztechnology system.[edit]
The Aztechnology SAN is pretty weak. Punch through it and move on to the next Node, an SPU. This one doesn't pose any threat either. After you defeat this one, you'll have a few choices to make. To get to where you need to be, you can choose to go to one of two SPUs: the one straight up or the one to the far left. I strongly suggest going straight up as the one to the left has a nasty Barrier/Tar Pit combination.
After getting through the second SPU, go to the next SPU to the left, which is only guarded by an Access and a Trace & Dump. After this, you'll have access to the CPU. Go on in, and don't be too scared. It has BlackIce, but no Tar Pit and the BlackIce is only Level 4 anyway. After you take out the CPU, go to the DS directly to the right (not the one a little bit down and right). Be careful, because this one has a Tar Pit. If you didn't use the double retreat maneuver (see Section XII) to get into the CPU, you may want to use it now. Once you're inside, just choose Transfer Data and you'll have the clue.
Get the clue from the Renraku system.[edit]
Despite the Renraku system being tough in general, the road to the clue is actually pretty simple. The SAN only has a Trace & Dump and the next Node isn't much tougher. After you get through that one, continue downward to the next SPU, which has Tar Paper. Just be careful and hope you don't trigger the Tar Paper because the CPU is next and you don't want to have to deal with it under Active Alert.
After disposing of the SPU, continue downward to the CPU. This one has Barrier and BlackIce, but shouldn't be too much trouble as long as you have a good deck and a talented decker. After you get inside, go to the DS that's just down and to the right. Be careful, this one has Tar Pit. If you didn't use the double retreat (see Section XII) to get into the CPU, it might be a good idea to use it now. On the other hand, the DS is only guarded by a Blaster, so one shot of Deception is all it takes. Once you're inside, just get the file and you're done.
Get the clue from the Fuchi system.[edit]
This one is probably the easiest of the runs. The SAN has no ice, so go to the next Node, which is an SPU guarded by only Access and Blaster. After you get inside, you'll have a whopping six choices for where to go. Go to the SPU that is far up and to the right. It has a lone BlackIce which shouldn't be that tough. From there, go up to an easy green DS, then all the way over to the DS on the far right side of the map. This one has BlackIce, but the primary ice is an Access, so just run Deception and you should get in relatively easily. Once inside, just Transfer Data to get the clue.
Get the clue from the Mitsuhama system.[edit]
This one can be a little tricky. First off, the SAN is weak, so get through and go to the first SPU. That one's a pushover too, so get inside where you'll have a few choices. Go right to the next SPU, which is armed with only a Trace & Dump, so it won't be much tougher than the Nodes you've seen so far. After you get in, continue straight to your right.
You'll come to another SPU which still isn't that much of a challenge. After this one, go to the SPU that's down and to the right. This one is slightly more difficult with Access and BlackIce, but still not that big of a deal. Get through and then move to the SPU that's up and to the right. This one can be kind of tough, but you should be able to take it. Finally, when you get in, go down to the DS below. It's another Node with Barrier and BlackIce, which I guess the game thinks is scarier than it really is. Get inside and get the clue.
Get the clue from the Ares system.[edit]
This system can be a real pain in the rear, even for the best character using the best deck. For one thing, its layout is very linear, forcing you to go through a long, narrow path. For another thing, the Nodes along the path are very tough, and a lot use Tar Paper and Tar Pit. My only advice is to save your game before you go in, and not to be afraid to use the double retreat move (see Section XII).
The Ares SAN starts you right off with a Tar Paper. Don't do anything stupid because if you trip it, there's no way you'll make it through the rest of the system on Active Alert. The next Node you get to, an orange SPU, gives you a break with only a Blaster. After you get through that one, go to the SPU far to the left. Be careful, as this is an exceptionally tough Node that uses Tar Pit. Hopefully, you'll be able to get by somehow. From inside the Node, go to the SPU straight up from where you are. This one's another break, guarded only by a Trace & Burn.
Go to the SPU to the far right and it's back to the grind, this time in the form of a high-end red Node with Killer and another Tar Pit. Hopefully, this will be a bit easier than the last Tar Pit Node, since you can use Deception to get by in one shot. After you beat it, go to the SPU that's straight up. This one is as tough as you seen, another red 5 Node that uses Barrier and Tar Pit. If you managed to legitimately get into the last Node, it would probably be a good idea to use the double retreat here. Regardless of how you get inside, your next move will be straight left to the next SPU, which is a bit of a break since it has no Tar ice.
After that one, continue to the left and you'll come to a red SPU with Access and BlackIce. Not too tough. From this Node, you'll see the CPU straight below. This is where you need to go, but it's one of the toughest Nodes in the entire game. Be VERY careful and use the double retreat if at all possible. After you manage to get inside the CPU, go to the DS just to the right of it. This one has Barrier and BlackIce, so it may be tough if your stats are on the low side, but otherwise shouldn't be too much trouble. After you finally get inside, pat yourself on the back and get the clue.
Get the clue from the UCAS system.[edit]
After you've gotten each of the five clues, you should be able to piece them together to find out that the corps are trying to sabotage the computer at a nuclear plant somewhere! Or something! Oh no! Actually, I don't think the notes make it very clear exactly what you need to save the world from, but the point is that you need to enter the Matrix system that uses the password that you've just pieced together: CHERNOBYL.
If you made it through the Ares system okay, then you shouldn't worry about CHERNOBYL. Go to a terminal and choose the password from your screen. It turns out that the passcode is for the UCAS Federal Government system. All you need to do is go to a certain DS in the system and get the clue inside, and you'll be done. Here's how:
The SAN is pretty easy -- just a Blaster. From the SAN, go to the first SPU, which is fairly easy as well. From that SPU, you're going to go straight down to the next one which can be tough. It has an Access and can therefore be defeated by a single shot of Deception, but beware if you fail: there's a Tar Pit lurking behind. After you get inside this Node, go left to another easy SPU. From here you'll need to go up and to the left to the next SPU. This one has Tar Paper, but the only other way to get to your destination involves going through a Node with Tar Pit, so you'll just have to tough it out.
After that Node, continue to the left to yet another SPU. This one is pretty simple, and after you're inside you'll have access to the final Node, which is... one of the weakest Nodes you've had to face in the entire quest. Oh well. Head down and to the left to the green (!) DS, guarded by a single Trace & Burn. Dispose of it, enter the Node, and download the clue. Congrats, you're done! Feel free to jack out and enjoy the cash and props from Sega.