What are The Two Letters?

The letter sent by Chula to Petrona, and the letter Petrona sends back, represent their sense of connection, friendship, and relationship. The sending of Chula's letter represents her determination to overcome the sense of betrayal she feels at leaving Chula behind: the sending of Petrona's letter in response represents her desire to keep the friendship alive, a friendship she values as one of the good things left in her life. The eventual fates of the letters also represent the attitudes of the characters towards the secrets they have kept for and from each other, with Petrona's letter representing her ongoing trust that Chula will keep their secrets, while Chula's burning of Petrona's letter representing her belief that the best way to keep those secrets is to end the friendship.