GW2 Hard Boiled is one of the the easiest achievements you can find in Dragon Bash achievement section. Hard Boiled comes after Ceremony and Acrimony achievement, and it’s also prerequisite for Every Piece Matters and No More Secrets.
Upon completing previous Achievement (Ceremony and Acrimony), you will receive a letter that points you toward Southeast Divinity’s Reach, where you are suppose to seek out for Marjory Delaqua. Interact with gate and enjoy the movie sequence. After the sequence ends, you will be granted with Hard Boiled Achievement, and a letter that guides you toward the next achievement.