Orc Rearguard
The Lost Realm#23 (x1)

No more than 3 progress tokens can be placed on the current quest each round.

While Orc Rearguard is the current quest it gains:

Forced: At the end of the staging step, reveal 1 card from the encounter deck.

Some of the Orcs have broken from the war party to hinder your pursuit. Until you deal with them, it will be difficult to continue your chase...