You are playing Nightmare mode.

Do not discard unresolved shadow cards from Shelob at the end of the combat phase.

While Cleft of Cirith Ungol is in the staging area, players cannot travel to locations not named Cleft of Cirith Ungol.

...she was there, who was there before Sauron, and before the first stone of Barad–d–r; and she served none but herself, drinking the blood of Elves and Men, bloated and grown fat with endless brooding on her feasts, weaving webs of shadow...
The Two Towers

Begin with the standard quest deck and encounter deck for the Shelob's Lair scenario.

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

4x Mogul Orc

2x The Under-way

3x Deep Dark Passage

2x Many Openings

Then, shuffle the encounter cards in this Nightmare Deck into the remainder of the standard Shelob's Lair 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.