The core of the DLC is that it adds rifts you can explore with a science ship. These look and behave much like the existing archeology dig sites. The scientist works them and occasionally you get presented with an event with a couple of options. Curious alternate universe stuff, not bad as far as stories go, but as soon as the work ends that is it. No continuing events like one of the "Dimensional Portal" alternatives. The DLC gives you another rare resource - astral threads - you can spend on bonuses. One of these is a new building you can unlock and upgrades. This building, its workers, produce the resource and massive quantities physics research allowing you to easily reach double of society and engineering empire wide. DLC adds a new origin and pre-defined race which might play into it better, somehow, which I haven't played yet. Overall it feels similar to the psychic and spiritual stuff already in the game.
