This page of the Deathloop guide has a walkthrough of the Visionary Lead/mission Chaos Theory. The walkthrough explains how to infiltrate Hangar 2 in Karl's Bay, where Harriet Morse is, how to get into the Visionary's office, and where to find clues about Frank.
Unlocking the mission
You will be able to start the described lead after completing Colt's prologue - The Longest Day The mission will appear in your journal after looting a safe in an apartment in the Updaam district and finding a document with the personal information and whereabouts of 8 Visionaries (bosses and main antagonists). However, we advise you to proceed with this task after you complete the Ubiquity mission. This will allow you to use the Residuum to keep the powers, weapons, and other equipment acquired during the expeditions permanently.
To deal with the described lead, you have to visit Karl's Bay in the morning.
Infiltrate Hangar 2
After reaching Karl's Bay, you need to go to the part of the district where are two large hangars. Harriet is in hangar 2. You can find hangar numbers on the walls.
There will be a lot of enemies around You can try to avoid them (Shift and Aether might be helpful) or eliminate them.
The entrances to Hangar 2 are locked, and the easiest way to get in is through the door from the side of Hangar 1. You can reach one of the main entrances to Hangar 1 or use Shift to get to its roof. In the latter case, you will be able to get to one of the windows on the roof and break it, to jump down to the upper balconies of Hangar 1.
Regardless of the chosen path, reach the above-mentioned upper balconies. You will find here a passageway between hangars 1 and 2 - they are shown in the attached picture.
Scour Harriet's office
When you get to hangar 2, you'll witness Harriet's "group session." If you get detected, you will be attacked not only by the surrounding opponents, but Harriet will also appear and join the fight. You can, of course, this opportunity to eliminate her and obtain the Nexus slab that she leaves behind (or its upgrade).
If you prefer to remain unnoticed, then as soon as you reach hangar 2, use Shift. First, teleport to the upper parts of the hangar to get above the place where the ritual was. Then teleport to one of the aircraft wings, next to the cabin from which the Visionary speaks.
Finally, we advise you to reach the left room shown in the picture. There are laser traps, but you can use the Shift to teleport through them without triggering an alarm.
Bypassing the laser traps will allow you to reach the area behind Harriet. On the current level, there should be only one opponent.
Get down to the lower level. You'll get behind Harriet. We recommend quietly eliminate her two guards and then going behind the Visionary and killing her with a sneak attack. You avoid fighting her, but her death still may alert the other people in hangar 2. If you do not want to fight them, then run quickly to the next level and wait until the situation calms down a little.
To complete the described lead, you need to find a minicom in the hangar where Harriet was. Reading the messages saved on the computer will end the task, and you will unlock a new mission, The Ballad of Ramblin' Frank - we have described it on a separate guide page.