Card Text:
You can't enter this dungeon unless you "venture into Undercity."
Secret Entrance — Search your library for a basic land card, reveal it, put it into your hand, then shuffle. (Forge, Lost Well)
Forge — Put two +1/+1 counters on target creature. (Trap, Arena)
Lost Well — Scry 2. (Arena, Stash)
Trap — Target player loses 5 life. (Archives)
Arena — Goad target creature. (Archives, Catacombs)
Stash — Create a Treasure token. (Catacombs)
Archives — Draw a card. (Throne of the Dead Three)
Catacombs — Create a 4/1 black Skeleton creature token with menace. (Throne of the Dead Three)
Throne of the Dead Three — Reveal the top ten cards of your library. Put a creature card from among them onto the battlefield with three +1/+1 counters on it. It gains hexproof until your next turn. Then shuffle.