- Q: How does Orphic Theory interact with Hidden cards? Hidden cards are treachery cards treated as if they are in your threat area - can I target a hidden card in my hand with Orphic Theory? Does that remove the Hidden keyword and allow the card to be discarded via some other means? A: Orphic Theory cannot target Hidden treacheries in your hand.
Spell.
Uses (4 secrets).
Spend 1 secret: Choose any non-weakness treachery not attached to an Elite enemy. Until the end of the round, treat that card's printed text box as if it were blank (except for Traits).

So... this thing does some pretty funny things.
It's hard to go into much detail without some spoilers, but among other things your whole party can probably ignore a particularly annoying encounter mechanic in Dunwich as long as the fastest-cycling deck has ONE copy of this card. And when searching for dream cities in the dreamlands there's another trap you can just waltz through. When this card works, it tends to be the key to your Locked Door.
It's very likely you're going to blank the discard condition for the card, so it is a stall unless you can push the game state to the point where something is either less relevant or irrelevant. That happens a lot though. And its cheap as dirt if you don't need the slot.