Paradrome Cube, the new Seasonal Artifact, and its associated quest are not exactly obvious to Guardians as soon as they get into the Season of the Splicer as the game will not automatically take or even direct them to the quest necessary to grab the gizmo.
Anyway, you will find the mission on Europa. It's named The Lost Splicer and accessing it is as easy as clicking the destination and then the light blue marker.
Enter the mission, protect the Smollen and watch the associated cinematics. When that is over, you will be directed to move to the new quarter in H.E.L.M., which is populated by the Eliksni.
You will notice a Servitor inside, which you can interact with in order to obtain the Paradrome Cube.
That's all there is to it. The quest is simple and quick but the actual trouble would be finding it, should you find yourself confused on where to start. The Cube has some interesting mods this season but there aren't any targeting ones so PvP builds will probably need to rely on the default mods that take quite a bit of space on the helmet slot.



















