Ultima IV: Quest of the Avatar/Dungeon Hythloth

The seahorse thread (Codex Chamber)
A short thread in Cove (talk to Allen, then Blissful, then the Ankh) allows to learn all the requirements to complete the game. If you followed this walkthrough, you already accomplished two (8-parts Avatarhood and the Word of Passage), and the next two are the Key of Three Parts and the Pure Axiom.

The unfinished thread (Pure Axiom)
Several clues are scattered through Britannia. First, Joshua and Juliet in Castle Britannia tell "the riddle" and give a hint to its answer. In Cove, four mages around a camp fire (Spellbind, Shaman, Charm, Circe) give more clues.

There is actually an unfinished thread towards the solution: talk to Dyka in Vesper, then to Francesca in Paws, and eventually to Smith, the talking horse in the same corral. It is a well known joke that the developers forgot to put the riddle answer in the game, so they put it in the next title.

Chuckles' thread (Key of Three Parts)
Zajac of the Lycaeum starts a new quest: he directs the Stranger to Chuckles of Castle Britannia, who in turn says to talk to the Water that can be found in a secret room in the same stronghold. The elemental spirit starts revealing where and how to obtain the Key of Three Parts: there are three Altar Rooms that connect the several dungeons; in each altar room the appropriate colored stones should be used. The passage guards in Empath Abbey repeat part of that information.

In the Lycaeum, an injured fighter adds that each altar room connects to four dungeons, and Tymus reveals that each altar room needs four stones. In Jhelom, Bengrod says that an altar room needs the stones found in the connecting dungeons.

The three altar rooms correspond to the three principles of Love, Truth and Courage. The eight colored stones correspond to the eight virtues.


 * Altar of Courage: Shyra of Serpent's Hold says to use the red (Valor), Purple (Honor), Orange (Sacrifice) and White (Spirituality) stones.
 * Altar of Love: in the Oak Grove in Empath Abbey, four characters reveal the virtues that spring from Love: Compassion (yellow stone), sacrifice (orange stone), justice (green stone), and spirituality (white stone).
 * Altar of Truth: the information about the last altar is more scattered; Quix & Skitle of Trinsic reveal that the purple stone (Honor) should be used on the altars of Love and Courage; Browning of Moonglow reveals that Honesty (blues stone) derives from Truth; Deirdre and Lastro of Empath Abbey reveal that Justice (green stone) is made of Truth and Love, whereas Spirituality (white stone) is made of the three principles.

Since the white stone of spirituality will be needed in all three altar rooms, it would be best to retrieve it first.

Thevel's thread (magic orbs)
Thevel of Britain directs the Stranger to the beggar Roderick of Serpent's Hold. The latter reveals that magic orbs can raise the attributes. These items are found in the dungeons.

Gather information
The location of the white stone is the most complex to learn about. Mitre of Skara Brae says it is missing from Dungeon Hythloth, and starts a dialogue thread: talk to the barkeep in Trinsic, then to Sloven of Cove, then to Isaac in Skara Brae. Result: you need to fly to reach its location atop the Serpent's Spine Mountains. In Buccaneer's Den, Sniflet says that a lighter-than-air-device is near the entrance of Dungeon Hythloth, but J.J. Scirlock reveals that the same dungeon can be accessed from a secret entrance in Castle Britannia. Damsel of Paws confirms the same information.

Dungeon Hythloth

 * Goals: get the lighter-than-air device and the White stone.

Before entering the Dungeon Hythloth, make sure you have plenty of the following spells:
 * Light (cheaper than torches)
 * Cure (for the chests with poison traps)
 * Dispell (to get past various energy fields)
 * Resurrect (to recover companions that touch the four Magic Orbs)
 * Wind (to drive the Lighter-Than-Air device)

Check the Magic page for details on the reagents and the ../Britannia Yellow Pages directory for the most convenient apothecaries.

Also purchase ten/twenty magic gems (you can use the "View" spell, but it is better to save nightshade and mandrake for other spells).

The maps of the floors are from the Amiga port, the screenshots of the rooms are from the Master System port.

The lighter-than-air device
Near the exit of Dungeon Hythloth lies the lighter-than-air device. get on it, and it will move according to the direction of the wind. It is therefore necessary to cast "Wind Change" spells to go in the direction you want. Actually, the exit of Dungeon Hythloth is quite faraway from the mainland in any direction, therefore you should just keep flying in the same direction.

The White Stone
Once you manage to get near the Serpent's Spine mountains (between Britain and Yew), locate the position of the White Stone shrine, align the balloon with it, then land on the hills near the mountains. Why? Because the wind is quite tricky; you should make sure you're aligned with the Stone, then cast the "Wind" spell in the required direction, then jump onto the balloon. When you're above the shrine, just Search it to grab the White Stone.

You saw how hard it is to fly with the balloon. Better leave it and rely on your feet from now on.