Somewhere in the multiverse, two intertwined Aperture Science labs have invented a way to link universes together. With the 1.21-Gigawatt Aperture Science Multi-Dimensional Multi-Generator, the test subject now has the ability to solve tests that span across more than one universe.

Follow the development of the Multi-Generator from conception up until "The Incident". Shift: Trichotomy is a Portal 2 map pack of three revolving around the concept of teleportation.

Watch out for the final and upcoming map Imminence.