From the publisher:
In The Three Trials, your heroes must recover the powerful Dunlending artifact, The Antlered Crown. However, to recover it in Nightmare Mode, they'll first have to survive the deadly challenges presented them by three Guardian enemies. The Three Trials Nightmare Deck brings these challenges more fully into focus with new Spirit enemies that both give strength to and gain strength from the Guardian enemies that share their totems.
Nightmare Decks for The Lord of the Rings: The Card Game allow you to revisit your favorite scenarios cast in the shadows of the game's challenging Nightmare Mode. Featuring deadlier enemies, darker locations, and more terrifying surprises, each Nightmare Deck introduces new, alternate encounter cards and instructions for using them to reshape a scenario's encounter deck. The result? A nightmarish journey through territory you thought you knew, but with twists and turns that will have you on the edge of your seat!