You are playing Nightmare mode.
"If simple folk are free from care and fear, simple they will be, and we must be secret to keep them so."
–Aragorn, The Fellowship of the Ring
Begin with the standard quest deck and encounter deck for the Intruders in Chetwood scenario.
Remove the following cards, in the specified quantities, from the standard encounter deck:
1x Angmar Orc
3x Angmar Marauder
2x Chetwood Forest
1x Outlying Homestead
2x Borders of Bree-land
1x Rugged Country
1x Shrouded Hills
3x Surprising Speed
2x Sudden Assault
Then, shuffle the encounter cards in this Nightmare Deck into the remainder of the standard Intruders in Chetwood encounter deck.
Finally, flip this setup card over and place it next to the quest deck. Its effect remains active throughout the game, which is now ready to begin.