It is unknown what the Holy Ones truly are, though the sourcebook indicates the possibility that they are ghosts, spirits, the true inhabitants of the tunnels beneath Bishopsgate, a psychic projection of said inhabitants, or simply Bodycombe's delusions.
Whatever the truth of the matter, their predations led to Bodycombe and his followers' mass suicide in 1857, leaving behind only two children as survivors — children who died shortly after, regardless.
The sourcebook provides three potential hooks in the modern day:
- That patients with no knowledge of the asylum's history are beginning to perceive them;
- That only the owner of Bodycombe's journal can perceive them, and the book has turned up recently; and
- The Holy Ones are manifestations or servants of the being Inothiel the Herald, a dark and twisted thing flung from Heaven and now trapped beneath the asylum.