You are playing Nightmare mode.

Forced: At the beginning of the quest phase, the player who is guarding Gollum must either exhaust a hero he controls or resolve the "when revealed" effect of the topmost Tantrum card in the encounter discard pile.

Forced: When Stage 4A is revealed, search the encounter deck and discard pile for 1 copy of Attercop, Attercop and add it to the staging area, if able. Shuffle the encounter deck.

Begin with the standard quest deck and encounter deck for the Return to Mirkwood scenario.

Remove the following cards, in the specified quantities, from the standard encounter deck:

3x Woodman's Glade

3x Wood Elf Path

3x Mountains of Mirkwood

2x Goblin Sniper

1x Marsh Adder

2x Wargs

2x Despair

2x The Brown Lands

2x The East Bight

Then, shuffle the encounter cards in this Nightmare Deck into the remainder of the standard Return to Mirkwood 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.