Vastness of Mirkwood
The Wilds of Rhovanion #37 (x3)
Treachery

When Revealed: Until the end of the phase, each non-objective location in the staging area gets +1 Threat (+2 Threat instead if it has at least 1 progress token on it). If the number of non-objective locations in the staging area is less than the number of players, Vastness of Mirkwood gains surge.