This was a mess.
Overview : Guy steals a "how to be a lich" book, you need to get it back-too late he's already a lich, run away.
Tower (cool demi-plane):
Enterance: guess the password, then make a check to say it even if you guess it
Floor 1: Search 3/4 things for the book titles, 4th is trapped. Odds of screwing players 87.5%
Floor 2 & 3: not meant to be solved until floor 4, unless you go down to floor 4 first
Floor 4: It's a bad sign when even the NPC points out the flaw in the module that both the category and script must be guessed with no clues whatsover. By pure chance they should get it by the 24th or 25th attempt.
Floor 3: Immortal enemies, and NPCs that may not be completely useless while party is getting pummled by life draining undead, thankfully once NPC discover nonsensical "solution" (only about 1/2 of them are actually paired correctly) then fight not so bad.
Floor 2: Math puzzle which inexplicably shifts and reverses half way though for no reason (162435 vs 342615)
Floor 5: Enivironmental effect which only matter until the NPC has 1 turn to dispell it.
Floor 6: Lich that gets a surprise round to kill the players as soon as the fight starts, then gets easily overwelmed if they focus fire on him (which or course they do).
[2 of 5 Stars!]