Vexa's Lab is a minidungeon in the Fireheart Rise, featuring jumping and teleportation puzzles along with a progressive boss fight at the end. Completing it awards the Vexa's Lab Explorer achievement.
The portal entrance is found near the vista west of Breaktooth's Waypoint in the western most part of the 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.
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 portals change their destination after completion of Vexa's event, so a bit of luck might be required to finish in one go.
A first pair of portals is accessible from the entrance, with one just to the right and straight ahead, the other accessible from the floor level. A failure at this point is not much of a setback, however, there are two portals that follow a successful portal. You may notice the concentric circles creating a target upon the ground floor. One of the portals will teleport you to the top of the room and drop you to your death. Should you find yourself in a heap upon the floor, you might be automatically revived at the beginning of this room, if it works properly and land on the pad. One portal is up the stairs to your right, oriented upside-down. The other portal is to the left after a set of stairways, the portal is oriented sideways and requires you to jump through the gateway. After this, one more portal brings you to the end of this 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 is defeated, 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.
- In the northeast corner of the final room, there is a pile of Waypoint Research Material, which is used to activate the Pile of Ley Line Dust required to craft a Cultivated Vine.
- In the southeast corner of the final room is Vexa's Test-Golem Remains, which is used to acquire Vexa's Golem Diagnostic Reader as part of Ad Infinitum III: Unbound.
- This minidungeon was added in the Shadow of the Mad King update.
- The last announcement before lab detonation "Ten seconds until lab detonation. Have a nice day!" is likely a reference to the movie Spaceballs.