Myste Williger was an accountant and a scribe before she was Chosen (by Aleirian) to be a Herald. In her time as a trainee she proved to be exasperating to Herald Alberich (Weaponsmaster's Second at the time) because of her complete ineptitude with weapons and her debilitating near blindness without corrective lenses. She was assigned to the position of Herald Chronicler's Second (under Herald Elcarth) after achieving her Whites. She became an occasional confidant of Alberich, the two feeling that they need not wear their social masks with one another.
While preparing for the last battle of the Tedrel Wars, Myste consulted the histories to determine possible routes for the invading forces and wrote up daily reports, proving herself useful despite her near blindness and lack of weapons skill. During the last battle of the Tedrel Wars, it was Myste who tackled Selenay out of her saddle and lay upon her, preventing the princess from engaging in combat with the Tedrels, likely saving her life. This maneuver broke Myste's ankle.
During the three years after King Sendar's death, Myste continued to show her usefulness to her Queen and country. She helped to disqualify potential Valdemaran suitors to Selenay, for which the Queen was very grateful. Myste then began to help Alberich with some reconnaissance in Haven by pretending to be her old clerk self. She was hired on by an acting troupe and helped uncover important information about the lead actor that led Alberich to realise Prince Karath was not what he seemed to be. During this period, she and Alberich became much closer. Alberich was not particularly receptive to her flirtations, but this was because he simply didn't realize what they were. Eventually, he did notice what she was doing and they became a secret couple. Many of the Heralds shortly found out, but were all kind enough to keep the secret.
Mercedes Lackey uses the nickname Myste, and has hinted that the character is partially based upon herself.
She was Chosen by the Companion Aleirian
She has Mindspeech, and other gifts are not discussed.
Details of her internship are not given.