Mrs. Gu Was Pampered so Beautifully and Delicately

The sister who had been dependent on each other since childhood was adopted by the Su family as a tool to gain access to the wealthy family, but died suddenly on the eve of her marriage. In order to find out the truth about her sister's death, she agreed to the Su family's request and married for her sister! But I don't want to get caught up in a bigger conspiracy, the mysteries come one after another...