You are playing Nightmare mode.
Setup: Each player gives 1 poison to a hero he controls.
Hundreds of angry spiders were goggling at them all round and about and above. It looked pretty hopeless. –The Hobbit
Begin with the standard quest deck and encounter deck for the Flies and Spiders scenario.
Remove the following cards, in the specified quantities, from the standard encounter deck:
3x Dark Bats
3x Hidden Path
2x Fighting Among Friends
5x Wicked Spider
1x Fat Spider
1x Giant Web
Then, shuffle the encounter cards in this Nightmare Deck into the remainder of the standard Flies and Spiders encounter deck.
Finally, flip this setup card over and place it next to the quest deck. Its effects remain active throughout the game, which is now ready to begin.
Forced: After a character is declared as a defender against Venomous Spider give it 1 poison.
Shadow: Give 2 poison to the defending character.
While Dark Colony is the active location, poisoned characters cannot ready.
Travel: A player at this stage must give 1 poison to a hero he controls to travel here.
Suddenly he saw, too, that there were spiders huge and horrible sitting in the branches above him, and ring or no ring he trembled with fear lest they should discover him.
–The Hobbit
X is the number of poison in play.
Forced: When this location is explored, make 1 hero unconscious.
Shadow: Attacking enemy gets +1 for each poisoned character you control.
While Patch of Midnight is the active location, treat the text box of each poisoned character as if it were blank (except for Traits).
Shadow: Raise your threat by 1 for each poisoned character you control.
When Revealed: Each player must either give 1 poison to each hero he controls, or reveal an encounter card.
Shadow: Attacking enemy makes an additional attack against the defending player after this one.