I've read a little Shirley Jackson (We Have Always Lived in the Castle is reviewed here) but I had no idea she wrote a novel like this. The Bird's Nest is the tangled psyche of Elizabeth Richmond, a dull 25 year-old orphan who lives with her aunt. She suffers from back pain and headaches so her family doctor refers her to starchy old Dr Victor Wright who fancies himself adept at psychotherapy. Wright isn't an actual psychotherapist, you understand, just an enthusiastic dabbler.
Wright hypnotises Elizabeth and unleashes multiple personalities - Lizzie, Beth, Betsy and Bess, who - rivals with one another - unleash chaos. The trick Jackson pulls off is to tell her story through different characters. The mark of her genius is that she doesn't do the obvious and split the narrative through the split personalities. No, she gives us Elizabeth herself, Betsy (the most active of the alternates), Doctor Wright (twice) and fiesty Aunt Morgen. Moreover, only the verbose, pontificating Wright narrates in the first person. It's very clever, beautifully done, and totally engrossing. No wonder The Bird's Nest is a Penguin Modern Classic.