Thendara House is a science fantasy novel by American writer Marion Zimmer Bradley, part of her Darkover series and a sequel to The Shattered Chain.

[1] The title refers to the Thendera Guildhouse of Renunciates, a religio-military sisterhood whose members live independently from Darkover's rigid patriarchal society.

[2] Magda Lorne tenders her resignation from Terran service to her supervisor, Cholayna Ares, saying that she has taken an oath to spend six months in the Guildhouse of the Renuniciates at Thendera.

Jaelle n'ha Melora starts her first day of working in the spaceport, but finds conforming to Terran customs a challenge.

She quickly discovers that her new husband, Peter Haldane, despite being raised on Darkover, has typically Terran sexist attitudes towards women.

An injured woman named Keitha knocks at the door and asks to take the oath, which will grant her refuge from her husband and family.

Several days later, Magda, Doria and Keitha undergo a consciousness-raising session with her future sisters regarding her motives for joining the Renunciates.

Afterwards, Jaelle mentions one guild member who is away on Sisterhood business, explaining that this organization is a remnant of one of the original groups that founded the Renunciates.

Russell Montray and Alessandro Li manage to offend their Darkovan hosts over the issue of airspace and local control.

Russell Montray and Alessandro Li become obsessed with meeting Andrew Carr, now called An’ndra Lanart.

As she decides to leave the Terran zone entirely, she learns that Alessandro Li has undertaken a journey to the Kilghard Hills without an escort.

In the storm, kireseth pollen is disturbed, giving Jaelle a vision of her daughter, Cleindori, in red Keeper's robes.

Magda has another hallucination of mystical voices, who identify themselves as the Dark Sisterhood, working for the long-term survival of Darkover.