The portal entrance is found near the vista in the western most part of Sloven Pitch. Just west of this vista is a cave pouring out a lava stream. Inside this cave are platforms that phase in and out. Wait for the platforms to phase in then jump and follow them into the cave. The platforms will phase out after some time, potentially dropping you into the lava below and forcing you to start from the beginning. If the platforms phase out, you can remain on them by staying on their frame-like edges. At the end of the path of platforms, you'll reach a portal that will take you to Vexa's Lab.
There is a secret entrance through the east side of the mountain south west of Vidius Castrum Waypoint which lets you skip the platform and lava part.
Near the entrance, Destroy Vexa's corrupted test subjects may be active. This consists of waves of various enemies, including destroyers, risen, branded, and icebrood emerging from the three gates. After these have been defeated, the containment cell will release a Veteran Risen Abomination. Once the event is completed or if it wasn't running upon your arrival, proceed through the lab door to the next room.
This room contains a number of stairways in various orientations, very reminiscent of M. C. Escher's Relativity drawing. These stairways lead to portals which will teleport you out from various other portals in the room. The first portal is just to your right and straight ahead. However, there are two portals that follow. You may notice the concentric circles creating a target upon the ground floor. The portal to your left will teleport you to the ceiling far above the target and allow gravity to take over from there. This portal is oriented sideways and requires you to jump through the gateway. Should you find yourself in a heap upon the floor, you may be automatically revived at the beginning of this room. The other portal, up the stairs to your right, is oriented upside-down and will get you where you want to go with only a little hop. After this, one more portal brings you to the end of this room. Alternatively, many players have had success simply making their way to the bottom floor then following the chain of portals up. This is the following easy way to pass this room: 1. From the entrance to this room turn right then you will see portal at your left (basically you can see this portal from the beginning enter to this room). 2. Enter to portal that in front of you, it was at the up stairway. 3. Same like number 2. 4. You can enter to the next room.
This L-shaped hall to the south-west has many large panels, some of which phase in and out, leading to the hall's elevated exit. Don't rely on them. Instead, stay along the brass railings to keep from falling. However, a number of golem assistants patrol these railings. They wont damage you, but they will push you off, causing you to have to start the room over. The latter half of this room in particular has a large number of these golems and no panels to walk upon. Thus it is very likely you'll find yourself falling off. Stability helps immensely, as it protects you from the knockback of the golems.
This room has numerous glass panels hovering over a water tank filled with sharks and the event Defeat Vexa and her golem. If you fall in, there are ramps on either side of the tank to climb out. On the bright side, you can disengage from the boss without it gaining its life back, so if you find yourself in need of health, you can distance yourself to disengage to rest. Kill-BOT has four moves:
Once the golem is defeated, Vexa appears in the center. The solid corners crumble and all platforms are destroyed, leaving you to walk on the brass railings to reach her. In addition, a number of turrets spawn along the railings. Work your way towards Vexa and take out nearby turrets. Vexa herself is of little threat, but occasionally, she'll do a blast which knocks players back and likely into the water. Once she is defeated, a Magnificent Chest will spawn in the center and players will receive the achievement credit. If you don't want to use waypoints to exit, there is an exit portal in the shark tank.
After Vexa dies, an announcement is made that "the lab will detonate in ten minutes". When the lab detonates, all players currently in the dungeon are transported to the entrance so the lab can reset to its initial state.
- This minidungeon was added in the Shadow of the Mad King update.