(I think I know,well at least what I think it will bring all of them toghether.A supernatural who knew where the location of Nirvana was betrayed the others by telling the Black Hand its location.I dontknwo a reason for his/her betrayal,we'll think of one.The Black Hand plans to destroy it and so they prepared THe Ultimate Weapon,a nuclear weapon that can destroy an entire island even a continent.Yet they are hiding it somewhere safe and theyll take it on the night of the Blue Moon which is going to happen in....i dont know you guys choose.WIth the link between Nirvana and Earth opened,and its location revealed,they will launch the weapon and destroy it killing lots of innocent lives.The Spirit of Nirvana,lets say a sort of God who makes sure that Nirvana is safe,feels the danger.It sends a sort of I dont know,magic links to all the supernaturals in both human world and Nirvana in which telepatically tells them the danger coming.But the supernaturals wont stay and do nothing.They willl all work toghether in order to face the Black Hand,find where the ultimate weapon is and destroy it.They will alo have to wipe out THe Black Hand and bring peace once again.What say about this?)