Cubic Gate
You can use an action to press one side of the cube to cast the _gate_ spell with it, opening a portal to the plane keyed to that side. Alternatively, if you use an action to press one side twice, you can cast the _plane shift_ spell (save DC 17) with the cube and transport the targets to the plane keyed to that side.
The cube has 3 charges. Each use of the cube expends 1 charge. The cube regains 1d3 expended charges daily at dawn.