How does Mrs. Drover control her fear?
After finding a mysterious letter on her hall table, Mrs. Drover retreats to the bedroom of her abandoned house to read its contents. In the narration that follows, we learn that Mrs. Drover's normal expression is "one of controlled worry," which suggests that she is already an anxious woman by nature. As she processes the contents of the letter, she moves from her position with her back to the empty room to a chair against the wall--an obvious sign of paranoia. Further, Mrs. Drover tries to convince herself that she is "in a mood" and has imagined the letter, but after shutting her eyes and opening them again, she finds the letter is still there. After locking the bedroom door, she hastily packs her belongings and prepares to--and eventually does--flee the house. Once out of the house and back in the presence of passersby on the street, Mrs. Drover is convinced that she has successfully escaped a dangerous situation. Obviously, though, this is not the case, as she presumably comes face to face with her Demon Lover in the taxi.
To cope with the mysterious letter from her dead lover, which has arrived without postage in her boarded up London house, left empty because of the bombing of London in World War II, Kathleen retreats to her bedroom. Having read the letter, she looks into the mirror, as if to reassure herself she is still alive and real, then busies herself kneeling and sorting through a chest which contains items she has come to retrieve. After that, she sits in a stiff-backed chair and decides to "rally herself" by saying she is in "a mood" and that the letter does not exist, but, of course, it does.
Kathleen tries to come up with a rational explanation for how the letter could have possibly gotten to the hall table of her locked and empty house. That does not work. She then steadies herself with a plan. She will call a taxi to take her to the train station as quickly possible. This comforts her as it will get her away from the house. Ultimately, however, it ends up differently than she expected.