What is a short summary of the story, Chastity, in the collection, There’s Something I Want You to Do: Stories?

Chastity takes place in Minneapolis and follows an architect named Benny Takemitsu. He is a friend of Elijah. (Elijah and Susan now live in Minneapolis.) One day, Benny sees a woman standing on a bridge, apparently contemplating suicide. Benny talks to the woman and tries to comfort her. Benny and the woman—Sarah—soon begin dating. They eventually marry and have a child together. Tragically, Sarah dies in a car crash not long after she gives birth.