Well, here we are, at the end of the first trilogy of Zork. How are you doing? I hope you haven't needed too much help along the way. In this game, you get to take on the Dungeon Master himself. maybe, just maybe, he'll let you share in some of his vast knowledge and wealth.
Ok, for starters, this game doesn't work on the same point system that the other two have been, in fact, there are only seven possible points to get in this game. Whenever I tell you to do something that will give you a point I will mark it with a number: 
Let's get right into the game shall we, I can tell by your vigorous clicking that you're anxious to finish this game. You start at the base of the Endless Stair.
Take the lamp and turn it on.
Walk South until you reach the shore of the lake.
Drop the lamp, you're done with it. (Really!!)
Jump into the lake. 
Swim West to the shore and then Go South into the Scenic Vista.
Take the Torch, and wait for the number on the table to change to "II".
Touch the table. 
Take the Grue Repellant and walk East.
Wait for the number to change to "III".
Touch the table again.
Drop the Torch.
Wait until you are taken back to the Scenic Vista
Go North to the Shore, Save your game and jump back into the lake.
Go down to the Lake bottom
Keep trying to get the Repellant and the Amulet.
Head back up to the surface and Swim South to the shore.
Spray the Repellant on yourself.
Go South, into the Dark place, and continue South again, then go East to reach the Key Room.
Take the Strange Key and move the manhole cover.
Go Down into the Aqueduct.
Go North to reach the Water Slide and North again to reach the Damp Passage you were in earlier.
Take the Torch.
Go West into the Junction.
Go South into the Creepy Crawl, and then South-West to reach the Shadow Land.
Save you game.
Wander around in the Shadow Land until you meet up with a cloaked and hooded figure. 
The Sword will appear in your hands.
Just keep hitting him  until he's powerless to defend himself.
Take his Hood and he'll disappear.
Take the Cloak.
To get out, go Eastward, and you'll end up in either the Foggy Room or the Creepy Crawl.
Either way once you get to one of those rooms, go North to reach the Junction.
Go West through the Barren Area, and West again to reach the Cliff.
Take the Bread.
Climb down to the Cliff Ledge. 
Wait until someone shows up above.
Trust him and tie the chest to the rope.
wait until he returns to the top.
Climb back up (with his help).
Take the Staff he offers you. (The Treasure is nice, but pointless in the game.)
Go back down to the ledge and down again to reach the Cliff Base.
Go South to reach to Flathead Ocean.
Wait around until a ship shows up on the horizon.
Say, "Hello, Sailor."
Take the Vial he throws to you.
Now comes the Fun Part.
Go East into the Tight Squeeze, and East again into the Crystal Grotto.
Go South until you reach the Great Iron Door.
Go East into the Museum Entrance.
Open the Eastern Door.
Go North into the Museum.
The Gold Machine is a Time Machine, and it works just fine.
Set the dial to 776.
Push the Time Machine South into the Museum Entrance, and East into the Jewel Room.
Get into the Machine.
Push the Button. 
Wait for the Guards to leave. (Listen to them for interesting factoids)
Take the Ring (Only the Ring you greedy bastards)
Open the door, and walk out into the Entrance.
Open the North Door and Go through it.
Put the Ring under the seat.
Turn the Dial to 948, and get in.
Push the button.
Exit the machine.
Look under the seat (You'll automatically take the Ring.)
Go South to the Entrance, and South again to reach the [Evil] Royal Puzzle.
Go Down the Hole, and then Push the South Wall.  Go East, South, East, and East
Push the South Wall, Take the Book, and Push the South Wall again.
Push the West Wall Twice, Go East, then South, and Push the East Wall.
Go North until you come to the Marble Wall, and then Push the East Wall.
Go West, South, South, South, South, East, East, North, North, North, and Push the West Wall.
Go East, South, South, South, West, West, West, West, North, North, North, West, North, and Push the East Wall THREE Times.
Go West, West, South, South, East, East, South and Push the East Wall.
Go West, West, West, North, North, North, East, East, and Push the South Wall TWO Times.
Go West, South, South, East, East, North, and Push the West Wall TWO Times.
Go South, West, and Push the North Wall until it won't move anymore.
Go West, and North.
Climb the Ladder.
Go North into the Museum Entrance.
Open the Eastern Door and take your stuff from the Jewel Room. (Funny how your stuff ended up in the Jewel Room, but the Time Machine went back to its original room.)
Head West until you reach the Great Door, and then Return to the Junction.
Go East into the Damp Passage, and North-East into the Engravings Room.
Shake the man awake.
Give him the Bread, and he'll eat it.
He'll show you a secret door, and vanish.
Open the Door and Walk through into the Button Room.
Go North to the Beam Room, put your Sword into the Beam and return here.
Push the button.
Go North to the Beam Room.
Go North into the Mirror Room, and North once again to enter the Rectangular Room.
Raise the Short Pole.
Push the White Panel TWICE.
Push the Pine Panel.
Go North to see the Guardians of Zork.
Drink the vial to become invisible.
Walk North till you reach locked door.
Knock on the door and The Dungeon Master will answer and let you in.
Go North, West, North, and North once more to reach the Parapet.
Set the Dial to 4.
Push the Button.
Go South, open the cell door and step inside.
Tell the Dungeon Master to go to the Parapet.
Tell the Dungeon Master to Turn the dial to 1
Tell the Dungeon Master to Push the Button.
Unlock the Bronze Door with the Key and Walk South to your Destiny!!
Encountering the Hooded One.
Attacking the Hooded One.
Reaching the Cliff Ledge.
Jumping in the Lake.
Touching the Viewing Table.
Pushing the button on the Time Machine with the dial set to 776.
Pushing a Sandstone Wall.
Say hello to the man at the Cliff
Try throwing things at the man.
Have you been eaten by the Roc or fish in the lake?
Eat the Algae.
Examine the key repeatedly.
Say "Hello Sailor." before or after the Boat is there.
Have you been at the Aqueduct View, on the Aqueduct, by the Giant Door, or been visiting one of the other Zorkians when the Earthquake takes place?
Have you seen the robot that takes care of the Museum?
Try walking into the Grue convention in the Dark Place.
Go to the Museum Entrance of the Jewel Room in 777.
Listen to the Guards or the Dedication through the door.
Look in the mirror or knock on the Door while you're invisible.
Try walking through the swamp or Quicksand.
Try burning stuff to meet the mystery guest.