Jane Barrett

In the novel Towards Zero, Jane Barrett is Lady Tressilian's elderly and devoted maid. At the time of Lady Tressilian's death, she was in a deep sleep.

It is later found that she had been drugged. Someone had spiked her senna pods with a sleeping drug. To Superintendent Battle, this suggested premeditation on the part of the killer and this contradicted the presence of a blood-stained niblick next to the dead body, which was meant to suggest a violent action in a moment of uncontrolled rage. This convinced the superintendent that things were not as straightforward as they seemed. Barrett told the police that before going to bed, she had heard Lady Tressilian's bell. She went downstairs to answer the bell and found Lady Tressilian was alive and well although she could not remember why she had summoned her maid. Along the way to Lady Tressilian's room, Barrett had also seen Nevile Strange going down the stairs and exiting the house. Barrett's statement provided an alibi for Strange, as it established that Lady Tressilian was still alive when he left the house.

Agatha Christie's Marple
In the 2007 ITV adaptation of the story. Barrett is portrayed by Amelda Brown. She plays largely the same role as in the original novel.