Talisman 4th Ed. - The Lost Realms Exp. - Rules of Play says:
This box combines the expansions The Nether Realm and The Deep Realms into a single package. It features 2 special Realm cards connecting the City and the Dungeon, 3 new Alternative Endings, 20 Bridge cards, 20 Tunnel cards, and 36 Nether cards designed to challenge even the hardiest of adventurers!