Negative Point
Negative Points were plotted locations in 20th-century Tokyo that contained small amounts of negative energy that could manifest a huge amount of Dark Power if wedges, such as the Dark Henge, were driven into them. They would then absorb Dark Power transferred from the 30th Century, and the amount of Dark Power absorbed would accumulate, thus growing until it reached its peak. If a full set of wedges were droven into several Negative Points, a Dark Gate would be able to open.
Negative Points were invisible to the naked eye, but a member of the Black Moon Clan would be able to track down the location of a Negative Point using their earrings.
Using Negative Points was an alternative to contaminating the Crystal Points as part of the Black Moon Clan's plan to destroy Crystal Tokyo.
