Exposure at Dejima — K. Bird Lincoln

In this short story set after the events of novels Tiger Lily and The Straw Doll Cries at Midnight, Tiger Lily and her lordling, Ashikaga Yoshinori travel to Dejima Island, the home of foreign doctor, desperate for a cure for Ashikaga's father, the Lord Daimyo's, mysterious illness. But someone else has gotten to the doctor first and Ashikaga will face the choice of saving the Daimyo. or exposing a long-held secret.