Where X are X we X now? (D.Gray-Man and Hunter x Hunter crossover)

A strange rift appears in Spain, the Black Order sends exorcists to investigate because a phenomenon like this could only be caused by Innocence. But of course the Millennium Earl isn't going let them get it without a fight! An Innocence causing that big of a phenomenon is suspected to be the heart!
So in the race to see who can get there first, exorcists Allen Walker, Lenalee Lee, Lavi Bookman, Kanda Yuu, and inspector Link, get sucked into the rift along with Noah's Tyki Mikk, Road Kamalot, and Shyril Kamalot.
They now find themselves in an unknown land with advanced technology and strange powers called Nen! Will they ever get back home?