Deirdre Dobson Foster

Deirdre Dobson was the pampered only-child of a wealthy Colonial sea merchant. At a young age, she was persuaded to marry her father's handsome business partner, Joseph Foster, a widowed sea captain from England. The couple had two children:  fraternal twins Matthew, who died of tuberculosis, and Sarah-Louise.

Book I:  Amber House
Sarah learns about her great-great-great-great-great-great grandmother from her neighbor Richard Hathaway. Amber House is rumored to be haunted, and Richard claims the locals all believe the haunting to be the troubled spirit of "Mad Deirdre Foster." According to lore, Deirdre was so stricken with grief over the illness and death of her only son, she went insane and was subsequently locked away by her husband, Captain Foster, until her death in 1776.

Sarah learns that the Captain was a sinister character who more likely abused his wife and her friend, the slave Nyangu. Sarah's first vision is of Deirdre, chained and locked in one of Amber House's attics by her husband. Deirdre threatens the Captain, telling him she can find him in his dreams.

In the climax of the book, Sarah discovers that Deirdre was able to escape into visions (or "echoes") while sleeping, and if another person with psychometric ability happened to share the vision, Deirdre would interact with that person. Throughout the book, Sarah's brother Sammy toted around a stuffed bear that belonged to Deirdre's son Matthew, which would cause Sammy to dream of Matthew and even dream he was Matthew. During one of these dreams, Deirdre "collected" Sammy, thinking he was actually her dead son. While rescuing Sam, Sarah discovers Deirdre did the same thing to Sarah's aunt Maggie in the 1960s -- Deirdre collected Maggie, believing her to be Sarah-Louise.

Relationships
In a vision of a teenaged Deirdre being courted by Joseph Foster, it is clear to Sarah that Deirdre is very taken with the Captain. It is implied that the relationship was one-sided, with the Captain only using Deirdre to access her father's considerable wealth.

Deirdre's closest non-familial relationship is with the slave Nyangu, who Deirdre attempts to free when Nyangu falls pregnant with the Captain's child. Nyangu is nurse to Deirdre's twins.

Appearance
According to Sarah, Deirdre was lovely when she was younger, with raven hair and pale blue eyes. But Deirdre is ravaged by her emotional strains, and her hair is streaked with gray in later visions, despite her relatively young age at the time of her decline.

Character traits and abilities
Despite the era in which she was born, Deirdre shows she is more than capable to stand up to her abusive husband. In one vision, she stabs the Captain with a dagger. She is not afraid of him, threatening him in Sarah's first vision in the attic. Deirdre is also shown to be fiercely loyal to those she loves -- specifically, Nyangu, Matthew and Sarah-Louise. She has the abiliity to see the past while awake and while asleep.