diff --git a/notes/game-descriptions.txt b/notes/game-descriptions.txt
index 85eea7f..7d9a645 100644
--- a/notes/game-descriptions.txt
+++ b/notes/game-descriptions.txt
@@ -5,8 +5,8 @@ New:
 * Bureaucracy
 * Nord and Bert
 * Sherlock
-- Trinity
-- Zork: The Undiscovered Underground
+* Trinity
+* Zork: The Undiscovered Underground
 
 New versions:
 - HGTTG
diff --git a/res/Pitch Dark.master games collection.do.not.edit.2mg b/res/Pitch Dark.master games collection.do.not.edit.2mg
index 151266b..a6dc8ad 100644
Binary files a/res/Pitch Dark.master games collection.do.not.edit.2mg and b/res/Pitch Dark.master games collection.do.not.edit.2mg differ
diff --git a/src/config.a b/src/config.a
index 57e9547..7b90eac 100644
--- a/src/config.a
+++ b/src/config.a
@@ -15,7 +15,7 @@
 ;
 
 !zone {
-kNumberOfGames = 31
+kNumberOfGames = 32
 gCurrentGame
          !byte $FD                   ; set at runtime
 kTextRootDirectory
@@ -53,6 +53,7 @@ GAMES                                ; length of this array must = kNumberOfGame
          !word .zorki
          !word .zorkii
          !word .zorkiii
+         !word .ztuu
 
 ; length-prefixed names of each subdirectory in game directory, 1 per game
 .amfv
@@ -148,6 +149,9 @@ GAMES                                ; length of this array must = kNumberOfGame
 .zorkiii
          !byte 8
          !raw  "ZORK.III"
+.ztuu
+         !byte 4
+         !raw  "ZTUU"
 
 .BEGIN_PARSER_DATA
 bInSectionName
diff --git a/src/prefs.a b/src/prefs.a
index 6e4e462..23005b3 100644
--- a/src/prefs.a
+++ b/src/prefs.a
@@ -7,7 +7,7 @@
 ; - LoadGlobalPreferences
 
 !zone {
-kDefaultGame              = 0       ; Zork I -- TODO fix this after adding other games
+kDefaultGame              = 28       ; Zork I
 kPrefsRecord              = $0800
 kPrefsLength              = 1
 kPrefsCurrentGame         = kPrefsRecord + 0
diff --git a/text/ztuu.txt b/text/ztuu.txt
new file mode 100644
index 0000000..58f89bb
--- /dev/null
+++ b/text/ztuu.txt
@@ -0,0 +1,46 @@
+[info]
+ ZORK: UNDISCOVERED
+    UNDERGROUND
+ 
+1997         Fantasy
+ 
+Difficulty:    ^^^&&
+
+[description]
+ 
+ The year is 1066. You are a Private, Seventh Class, in the Inquisition
+ Guard. After being relieved by Earl at the Port Foozle Inquisition Gift
+ Kiosk, you find yourself standing in the Headquarters of Frobozz
+ Electric. Gesticulating in front of you is the Pastor of Disaster, the
+ Minister of Sinister, the Grand Inquisitor. It appears he has a very
+ special mission for you.
+ 
+ "It is with great hope and expectation I send you on this mission," the
+ Grand Inquisitor intones, his voice booming like distant, rumbling
+ thunderheads. "We have discovered what appears to be a piece of the Great
+ Underground Empire, never before explored. I would have sent Grubald the
+ Bold, but he's busy. As is Matchlick the Mighty. So, 'tis you."
+ 
+ "What of Linklaw the Lucky?" you ask shyly.
+ 
+ "Laid up. I'm afraid 'tis you and none other. A simple, solo quest, one of
+ fun and mirth, mischief and merriment, a jaunt, an excursion, a simple
+ outing. Merely explore, enjoy yourself, and bring back news of what lies
+ there, long-ago buried for countless ages."
+ 
+ "And Fretsham the Fortunate?" you ask hopefully.
+ 
+ "A fatality!" the Inquisitor booms. "Here," he says with evaporating
+ patience, "take these and be of good cheer." He thrusts into your hands two
+ things: a brass lantern of dubious quality, and a plastic sword of no
+ antiquity or use whatsoever.
+ 
+ "But what of Kolchack the --"
+ 
+ "Enough! Kolchack is contracted. Remember, who is the boss of you!" He
+ pauses briefly as if awaiting a reply. Then without warning, he answers his
+ own question. "Me! I am the boss of you! Now begone!"
+
+[versions]
+R16.970828.Z5=r16 / 970828
+