Item from Throne of Glass by Sarah J. Maas
The barrier between worlds — the cosmic door that separates Erilea from the Valg dimension, held shut by the Lock that Aelin forged with her own life force.
The Wyrdgate is the series' ultimate stakes — the door between everything and oblivion. When it opens, the Valg pour through. When it's sealed, the worlds stay separate. The entire eight-book arc builds toward one question: who will forge the Lock that seals the gate permanently, and what will it cost them? The answer is Aelin, and the cost is everything she has. The Lock requires the wyrdkeys and the life force of a world-walker to forge — a sacrifice that should have killed her. That she survived (barely, through the combined sacrifice of her allies) is the series' final miracle.
Not a physical object in the traditional sense — the Wyrdgate is a dimensional barrier, visible only through wyrdmarks and magical perception. When open, it appears as a tear in reality — darkness beyond darkness, the howling void of the Valg dimension pressing against the fabric of the world.
Also known as: The Wyrdgate, Wyrdgate, The Lock, The Gate Between Worlds