Secret Stair
The Betrayal of Mîm #184 (x3)
Treachery

Surge.

When Revealed: Attach to an enemy in play. (Counts as a Condition attachment with the text: "Limit 1 per enemy. Each enemy in play gains relentless.")

Shadow: If this attack destroys a character, add 1 encounter card to the staging area of a random non-unique location.