Codex of the Infinite Planes

Codex of the Infinite Planes, also known as Yagrax's Tome, was a cursed artifact that held terrible power.

Description
The Codex was far larger than a tome should be. A pair of strong men could barely lift the tome. Deep black obsidian was used for the covers. The pages were sheets of hammered lead thin enough to fold like paper. Every page was illuminated with bizarre markings in an unknown language. The reader always found another page no matter how many times the pages of the Codex were turned.

Powers
Every power within the Codex was triggered by reading. The Codex was capable of opening a portal to any plane of existence or any location on a Prime Material plane. The Codex could summon a greater fiend to serve the reader for a full day.

Each use of the Codex posed a cumulative risk of driving the reader utterly insane, unleashing a catastrophic event, or inadvertently summoning a greater tanar'ri.

History
The origins of the Codex of the Infinite Planes remained unknown.

Notable Owners
Emirikol, a plane-traveling wizard, had possession of the Codex of the Infinite Planes at one point.