Vivien Leigh, well-known for her portrayal of Scarlett O'Hara in 1939's "Gone With the Wind", plays Blanche, a Southern belle as fragile as Scarlett is strong. In a way, Blanche is what Scarlett would have become if she had watched her mother die. "Death is very pretty compared to dying," she tells her sister Stella, who only came home for the funeral.
Stella is pregnant and married to Stanley (the inimitable Brando) who both abhors and is fascinated by his sister-in-law Blanche (and not just in a platonic manner.) Blanche in turn is interested in meeting new gentleman callers, as her great love once killed himself (as she tells us in one of the most riveting scenes in movie history.) Interesting note: the delivery boy she flirts with is Mickey Kuhn, who once played Leigh's nephew Beau in GWTW.
Blanche is so fragile that she has no choice but to break. Unfortunately, others hurry her down that path. Perhaps the worst thing one can do, it seems, is depend on the kindness of strangers.