You're headed for the signal processor to enter a code to repair the signal system. Once those repairs are made, you'll have to deal with interference from the cannabis virus as you pilot your way to the signal room and then restore the communications interface's third key so that you can leave.
Compared to Parity, this level is a breather—a shorter, less dangerous, more straightforward code-based mission. The only serious challenge here might be if you suffer from motion sickness, what with a cannabis trip being part of the level theme.
Maintenance room[edit]
You begin on the north branch of an reverse-"S"-shaped causeway over Matma in the maintenance room. Spin southeast before descending to scout the opposition, which will include one, three, or four clamps nearby. Confirm their locations on your HUD map if you have a hard time picking them out from a distance. When you're ready, select your double eraser, drive down until you have a clear shot unimpeded by strobe lights on the ramp's border, and engage them. The moment you hit one, the whole group will respond, so be ready for return fire. Some will try to duck behind strobe lights, so you might need to strafe, and watch out also for clamps in the back deciding to retreat to surprise you later.
Head right toward the south branch and pick up any items you need, but don't get too close to the one, three, or four clamps directly across the way. (Their detection ranges are marked for your reference on the map on this page.) As you round the south branch, keep them in your crosshairs in case they do get suspicious, but plan on taking them from even ground and not before. (If you are good with pitched weapons, it is also possible to fire on them from below, but otherwise that's a bit riskier than necessary.) Once the obvious clamps are gone, check to the southeast for two more hiding out toward the Matma on hard.
Optionally, if you want a clue for the next puzzle, you can continue onto the lift in the center of the south branch's terminus. Riding it up will bring a blinking red pillar and a couple of items into view to your east. Combined with the fact that the large green block is in the way of the exit ramp to the south, those inaccessible items suggest that there should be some way to lower the block. Unfortunately, the cost of this clue is that the lift does not descend, so you'll have to jump off (do so slowly) and refresh your data.
Climb back down the ramp and leave the "S" on a path to the east. The path is clear on easy and medium, but on hard it is guarded by another pair of clamps. Strafe around the green block to find one, two, or three further clamps behind it and among the northernmost orange sockets. You now need to enter the code to repair the signal system. (Yes, you could bypass this puzzle by jumping diagonally to the ramp below, but you would permanently miss one of your mission objectives.)
Between the orange sockets, notice how the wall segments are labeled with silver dots and dashes. There are six dots and three dashes, so what common code does that remind you of? Unfortunately, most of the dots and dashes seem unresponsive, but if you stroll all the way to the left, the dot at the end does disappear if you tap it, making the same sound that you heard when pressing keys in Parity. So continue entering "SOS" (dot-dot-dot, dash-dash-dash, dot-dot-dot) always tapping the southernmost match for the symbol you want. If you make a mistake, the puzzle will silently reset. When all nine symbols have disappeared, a message will tell you that the signal system is repaired, and the green block will lower. Be ready to jump on it as soon as it comes level with the floor since it will keep descending, and you don't want to subject the Skaphander to a nasty fall.
Collect items as necessary and head for the room exit. Sadly, there is no way to avoid the joint the cannabis virus left you, but its effects are not too bad yet—warping of the camera frustum, some girlish laughter, and Victor's inner monologue going "Oh my God, I'm stoned!" from time to time. Acclimate to the camera-screw and, on hard, wipe out the two clamps guarding the entry to the lift-control room.
Lift-control room[edit]
The lift-control room is a large rectangular room with stripes of Matma along the south and north and the three letters "SOS" embossed on the floor. Two, five, or nine clamps are present, but their detection and communication radii are too small to make them much of a threat. In fact, since the clamps are so spread out and badly placed to double-team you, and because you have a lot of data refreshes in this room, a good option if you need to conserve your energy is to use dual-mounted debuggers here rather than your double eraser.
When the room is safe, hold off on refreshing and recharging for just a moment and go press the button in the southeast. The lift between the maintenance room and this room will reactivate, and the letters will sink into the ground giving you access to the best items. Restock on data and energy, trying to leave as much as possible for later. Then head back west and, being careful to not overshoot it with your addled perspective, ride the elevator up to a northbound hallway.
Trip[edit]
The trip is a complex of black halls with moving red and yellow gridlines outlined in teal. Except on easy, one or two clamps may be waiting for you as you ride the lift in, and their gunfire could kick you back off the lift, so prepare to charge even as you're ascending. Once you enter the trip, focus on the still walls, not the animated floors and ceilings, because they will give you a more accurate sense of motion. Your HUD map is also a good way to keep your bearings.
Proceed north and, if you didn't run into the patroller already, catch it as it pops out from your right. If you need data, continue even farther north to refresh and also pick up the breakpoint back there, but otherwise save that deadend for later since there's no way to get to the breakpoint without driving over the refreshes. Next, drive east to encounter another clamp on medium or hard and skip the first left turn, heading for the second instead. That will lead to a small room's backdoor and one or two more clamps.
Inside the small room are a repair station, an energy station, and a booby-trapped gold bug. Use the stations first, and then face south to squash the bug, backing up hard so that you can find the one or two clamps that spawn. On medium and hard there will be one in the center to hold your attention and a second to the side that will try to sneak up behind you. Follow the eastern corridor back to the main hall, ignore the side paths again, and trace it all the way to a northeast corner where a clamp is hovering and then south to a four-way intersection.
At the four-way intersection, you have refreshes to the west and a clamp-guarded breakpoint to the east. Dispatch the clamp and take what you need, then continue south to a T-intersection with three clamps on the left, which you should handle first, and three more on the right, which you should worry about second. At this point you may be running low on energy, so it's a good time to backtrack to the passages your HUD still shows as unexplored. They form a large "U" with zero or two clamps in the back and a lot of unavoidable items; traversing the "U" clockwise from the west will leave you in pretty good shape when you come out the east end.
Back at the T-intersection, take the right, which will bring you to a socket-lined corridor that cures the visual effects of the cannabis if not the audio loops. Fell the clamp around the bend, but don't bother riding a lift back down to the lift-control room unless you're really tight on resources. Rather, return to the "T" and cross to the east. One more U-turn will bring you through one, two, or three clamps to the signal room's door.
Signal Room[edit]
The two-window signal room is iced over, with most of the floor being frozen data, but some sections are marked out in a darker blue or in red. There are one, three, or five clamps in residence, one of which you can probably see from the door, so shoot it down and then wait for a second clamp, alerted to your presence, to reveal itself. The others you will have to fight on ice, but if you shoot from a distance, you can engage them one at a time. Patch up your data, but don't gather any energy.
There's a bug in the middle of the red part of the floor, but if you try to drive straight to it, the red floor will repel you. However, notice that the blue tiles spell "SO", leaving a blank in the red rectangle where the final "S" needs to go. Trying to drive along an "S" from the northeast doesn't work, but if you start from the southwest, you can progressively change red tiles to blue, collecting 300 energy and the bug along the way. That finishes the key to the communications interface, lowering the obstruction in front of you to reveal the exit. But it may also reveal as many as one, four, or seven clamps.
Fortunately, these clamps are all starting well below ground level, an angle from which they have trouble firing. A few volleys with the interrupter are not a bad idea as long as you remember to aim low to compensate for recoil. Then you can either plant yourself on a stable tile and fight with a pitch-down eraser, or you can back up and let the clamps escape one by one. But be aware that the now-blinking "S" you drew is temporary and will eventually revert to a red rectangle and repel you, so the regular blue tiles are better camping spots. When the way is clear, stock up, hop down into the socket-lined corridors, destroy the one, two, or three clamps still on the side branches, take your fill of items, and enter the escape shaft.