Who is Druot from Perfume and what is their importance?

Druot is Madame Arnulfi's lover, as well as a journeyman perfumer in her shop. After her period of mourning is over, the couple marries and Druot becomes a master perfumer. When Grenouille is finally acquitted of the murders in Grasse, Druot is arrested and tortured into confessing to his guilt. As a result, he is setenced to hang.