Given to the Bitter Blades by the “scholar” Damien Nuren. The cube is 2 inches on each side. It is heavy, as if made of stone or lead, but is enameled in black on five faces and is made of silver on the other. Characters are instructed to press the silver face one time to activate the cube, and a second time to turn it off. Damien claims that the device is a “Cube of Location”, which will tug the holder toward the hiding place of a specified item (as per the spell locate object).

When the silver side is pressed, the cube opens a planar vortex linking to the Plane of Shadows. The area in a 40-ft. radius centered on the cube simultaneously exists in both planes, for as long as the cube is active. The area is affected as if by a Darkness spell, and 1d6 shadows immediately appear in the area.

At the same time, similar 40-ft. radius area of light appears on the plane of shadows. Any creature native to the plane of shadows stepping into this area can freely traverse to the corresponding location on the material plane (and vice versa). Creatures on the material plane side who understands the true operation of the cube can also freely pass between planes in this way, as can any creature that succeeds on a Portal Feel or Planar Sense proficiency check.

If left active and unattended for an extended period of time, 1d6 additional shadows (or similar creatures) will pass through the vortex into the material plane every hour that it remains open.

The cube can withstand 20 points of damage before it is destroyed, and is allowed to save as a hard metal object vs. crushing blow. If the cube takes enough damage to be destroyed, it explodes in a 2d6 fireball affecting everything within a 20-ft. radius.