The Vaults beneath Chateau Haine are an extensive repository for the considerable supply of valuables amassed by the Montfort family. The Vaults are home to not only a vast collections of jewels and similar valuables but also rare armors and weapons, all of which are guarded by a complicated series of traps and locks.
For a complete detailed walkthrough of solving the puzzles see Heart of the Many: The Vaults.
There are three puzzles within the vaults, and solving one extinguishes the curtain of flame that surrounds the centerpiece of the vault. All three puzzles require two parts; the first to resolve a puzzle in one of the side passages which nets some treasure as well as a clue to resolve the second part.
When a puzzle has been resolved, the framed black painting in that area will fill with a curious picture of men, some masked, some not. This clue will help Hawke resolve the second part. When Hawke flips the floor panels in the main vault to match the pattern revealed in the paintings in the adjacent corridors, the valves feeding the flames shut off, leaving the treasure they protect, pieces of the class-specific Messenger, Orlesian Lancer, and Enchanter Illana armor sets accessible.
The first two puzzles present Hawke with a device and two runes of different colors. Doors corresponding to these runes will only open while Hawke is affected by the rune of the same color. Two of the colors, blue and red, may be mixed on the machine by touching the first color, then the machine, then touching the second color, then the machine, then touching the resulting rune it produces before opening the door. Before gaining access to one of the last colors needed to mix the final color, a Rune Golem will challenge the party and must be destroyed.
The third puzzle appears to be a pattern of floor tiles that flip along with their adjacent neighbors, to reveal a portrait of Prosper, apparently in his younger days. Because the tiles flip their neighbors, and a single tile may be affected by at least two others, they must be flipped in a pattern to reveal the entire portrait.
Resolving the last puzzle in the vault shuts off the remaining flame and reveals a chest containing the Coat of the Messenger, Orlesian Lancer Armor, and the Robes of Enchanter Illana completing the set. (Armor dependent on Class)