At the beginning of Shadowkey, the hero is living in a town known as Azra's Crossing, when it is suddenly attacked by bandits. The hero manages to fight off the bandits and saves the inhabitants of Azra's Crossing from Delfran, the leader of the bandits. Inside Delfran's hideout the hero finds Skelos Undriel, a shadowmage who tells him that more may be at stake, as well as a Shadowkey, a strange artifact.
Back at the village, Skelos tells the hero that he is being hunted by Jagar Tharn, and that he needs a place to hide until he is safe. After the hero clears Earthtear cave to use as a hideout, they are told that somebody is using the ongoing War of Bend'r-Mahk to create a powerful entity known as the Umbra' Keth (also known as the Shadow of Conflict). Skelos urges the hero to realise that this entity must not fall in to the hands of Jagar or any other mages of his kind.
Fortunately for the hero, Skelos tells them of a solution; the hero must find the five Star Teeth, enchanted crystals with the ability to fight Shadow Magic. Skelos tells the hero their location, and the hero then goes off to retrieve them. Inside the Twilight Temple, the location of one of the Star Teeth, the hero finds Pergan Asuul, a powerful shadowmage looking to control the Umbra' Keth. Once Pergan is defeated, he tells the hero that they will fight three more times.
Continuing the search for the Star Teeth, the hero reaches the Fearfrost Caverns, where a large crystal lies. As the hero approaches, the crystal reacts to the proximity of the hero's shadowkeys, and breaks open. Inside the crystal resides a mage, who appears to have amnesia. It turns out this amnesic mage is Azra Nightwielder, the first ever shadowmage. He asks the hero that they speak near Azra's Crossing, where he tells the hero that there are in fact seven Star Teeth, not five. Azra gives the hero the location of the final Star Teeth.
At the Glacier Crawl, the hero finds Captain Nym, who tells the hero of the origins of the Star Teeth, that they were taken from the sky with airships. He may or may not have given the hero the Star Coif, depending on if the hero had all seven Star Teeth at that point.
Once the hero had obtained all seven Star Teeth, the hero could finally face and destroy the Umbra' Keth at the Crypt of Hearts. Inside the crypt, the hero finally defeats Pergan Asuul, and moves on to fight the Umbra' Keth. The hero lead the entity to the Vault of the Heavens, and places down the Star Teeth, making the Shadow of Conflict vulnerable.
Once the hero defeated the Umbra' Keth, the threat is gone. The fate of the hero after this point is unknown.