The Tharchiate Codex

The Tharchiate Codex is a Legendary Book which allows the reader to fully unlock the secrets of the Necromancy of Thay.

WARNING: Extremely powerful knowledge. May include curses.

Properties

• Books
• Rarity: Legendary
•  Weight: 0.5 kg / 1 lb
• Price: 2000 gp

Where to find

The Tharchiate Codex is stored in the Sorcerous Vault beneath Sorcerous Sundries in the Lower City. The vault can be reached in two different ways:

• By interacting with the Clasped Book in the bookshelf of Tolna Tome-Monger's office upstairs and going through the portal, or
• By using the Weave Button labelled 'Vault' on the middle level of Ramazith's Tower.

Within the vault, the Codex is located in the Elminster section. To unlock the Elminster door, the party must first find the lever at the end of the Silverhand section by opening doors in this order: Silverhand, Evocation, Wish. Alternatively it's possible to unlock the Elminster door using the  Knock spell.

Text

[The pages are covered in esoteric symbols and strange runes, some indecipherable, but some strangely familiar. Your eyes are drawn to one page, describing a long-lost book.]

The Necromancy of Thay

There are secrets of life and death known only to the Red Wizards. Committing such secrets to parchment is a risk they are loath to take, lest the unworthy gaze upon them. Who better, then, to guard their secrets, than the spirits of the jealous dead themselves?

To look upon the Necromancy of Thay is to risk madness at the hands of its spirits. But the wise traveller, who can tread the line between life and death, will find knowledge witnessed by precious few mortals...

[The rest of the entry details the precautions and risks associated with reading the text, but lays out a clear path to unravelling the secrets contained in this tome.]

Notes

The first character to read the book receives the following effects:

•  Tharchiate Withering, which lowers the Constitution score, this can be cured with  Remove Curse or  Greater Restoration.
• After removing the curse:  The Tharchiate Codex: Blessing, a passive feature, which grants  Tharchiate Vigour (20 Temporary Hit Points) immediately and also once after every Long Rest. Characters with this condition will lose it immediately after using Withers' Class Change service, but the condition returns after the next long rest.

After reading The Tharchiate Codex, it's possible to re-read Necromancy of Thay and pass a DC 20 Wisdom saving throw to gain the permanent ability to summon 4 ghouls via the  Danse Macabre spell once per Long Rest.