She met Morrolan during the Interregnum, while travelling in the East, and accompanied him to the Dragaeran Empire while he assisted with its restoration. (See The Paths of the Dead for an account of their initial meeting.)
She was instrumental in the creation of Castle Black, and remained there for several hundred years as seneschal and Morrolan's friend.
Morrolan claims that at one time, she watched over his body and kept it alive for several days while his mind and soul journeyed elsewhere. This is said to have been no small task.
However, she became involved in a battle with the Jenoine, during their attempt to take control of the Lesser Sea of Chaos. Becoming enraged when the Jenoine killed Morrolan, Teldra determined to avenge his death by attacking the Jenoine responsible.
As befits her House, she struck suddenly, accurately and without warning, using a very strong Morganti dagger that she took from Vlad Taltos. The Jenoine was wounded by this, but not killed, and it pulled the Morganti dagger from its own body, and slammed it into Teldra's chest, killing her almost instantly.
As she lay there, Vlad Taltos rushed to her side. In a strange moment of intuitive witchcraft, he used Spellbreaker to send his consciousness into the Morganti dagger, and struggled with it as it was in the process of consuming Teldra's soul. He gathered the fragments of Teldra's soul together, and bound them, together with Spellbreaker and his own soul, to the dagger.
It is unclear what happened to Teldra's mortal remains after the battle, although it is likely that they were taken to Deathgate Falls.
Her soul has survived as part of the Great Weapon, Godslayer, borne by Vlad Taltos, who even refers to the dagger as "Lady Teldra". It has been hinted that at some point she will once again "wake up". While this has not yet happened as of the events of Iorich, it does occur in as of Hawk -- she occasionally has stream-of-consciousness outbursts within Vlad's head, and on one notable occasion, Sethra is able to hear one.
Vlad had wondered if it would get crowded with another voice in his head; apparently it doesn't, since Teldra's thoughts are not audible to Loiosh, and it seems to take Vlad some time or effort to even separate them from his own. His communication with her is still quite limited, and he's not yet sure when she is and isn't responding.
There have been hints that Vlad is being influenced by her in some undefinable way; he is perhaps calmer and more polite when he is in physical contact with the weapon.
She was described as being beautiful and slender, with light brown hair and green eyes (typical for an Issola). Vlad wonders how she achieves such beauty without apparent sexuality. Also typically for her House, she was a born and trained diplomatist, a master of many protocols and languages (including the language of the Jenoine), and almost impossible not to like. Vlad believes that part of her likeability lies in that she herself genuinely likes people.
"Do irony and grey laughter help ease your fears?"
Referring to the Jenoine's odd behavior:
"They probably weren't raised on the right sorts of bedtime stories and songs."