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 (Leads to: Forge, Lost Well)
Forge — Put two +1/+1 counters on target creature. (Leads to: Trap!, Arena)
Lost Well — Scry 2. (Leads to: Arena, Stash)
Trap! — Target player loses 5 life. (Leads to: Archives)
Arena — Goad target creature. (Leads to: Archives, Catacombs)
Stash — Create a Treasure token. (Leads to: Catacombs)
Archives — Draw a card. (Leads to: Throne of the Dead Three)
Catacombs — Create a 4/1 black Skeleton creature token with menace. (Leads to: 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.
Near Mint - $20.70
Lightly Played - $18.60
Played - $14.50
Heavily Played - $12.40
Damaged - $10.40
Near Mint Non-English - $20.70
Lightly Played Non-English - $18.60
Played Non-English - $14.50
Heavily Played Non-English - $12.40
Damaged Non-English - $10.40