The Weird Sisters are three sisters named Nimue, Vivienne and Morgause, who live in Wellington Wells in the Garden District. supposedly witches. They live on a small thunderstorm-covered hill called the Witch Peak on Lud's Holm.
At a young age, Sally Boyle visited the witches in order for them to make her more girly, but they said that it was not needed. They told her to pretend to be that way instead, and also told her to save her chemistry skills for the future, seemingly aware of what was to happen to Wellington Wells.
At some point, they joined Harry Haworth's team, who were responsible for the creation of Joy, a decision that they would come to regret much later. Years later, they helped Sally Boyle decide what to do in regards to the fact that she was pregnant, and they helped her prepare for the baby's arrival.
They eventually went off Joy and became Wastrels, living in the Garden District on top of a hill. They worshipped an unnamed being that they simply referred to as the Goddess, however writing can be found by their chest that refers to the sisters as the "Cult of Hecate", who is the Goddess of Magic in Greek mythology. They also practiced "witchcraft" and "magic."
Events of We Happy Few
Arthur Hastings can find a chest of theirs in the Garden District, containing valuable supplies. This chest refills after a couple of days.
Several memories of the Weird Sisters can be discovered by Sally around Wellington Wells. Eventually, Sally needs help from the Sisters to replace her ingredients in order to make more Blackberry Joy for the Bobbies. They agree to help her, but first make Sally carry out several tasks. The first involves placing sacrificial bricks in a chest, which makes Sally stronger (and able to carry more). Sally then heads back for more orders, and receives some recipes. The next task involves Sally investigating a disturbance at one of their holy sites, a miniature Stonehenge of sorts. There, Sally discovers a suicide cult planning to kill themselves with poison soon to move on to a higher plane of existence. Sally returns to them, clearly disturbed, and asks them to help her stop the cultists. The Sisters then give Sally a recipe to render the poison drinkable and also make it a "revealing" hallucinogenic liquid.
Sally goes to the cultists' hideout, puts the antidote in the liquid, and witnesses the cult come to realize that their leader is a lonely old man who wants to die with others. After dealing with the cult leader, Sally returns to the Sisters, who finally tell her the ingredients needed to replace the ones that were destroyed and give her more recipes. Sally thanks the Sisters and leaves.
- At one point, they make a fourth wall break, mentioning how the "one who is three" is coming to the "three who are one." This is referring to the fact that Sally is one of three playable characters who the player controls, and possibly refers to the player themselves.
- Sally is skeptical that the Weird Sisters actually use magic, although can't figure out how they appear and disappear suddenly (when she looks away for a moment). She also is suspicious that the "magic" that makes her stronger is psychosomatic (which they say doesn't really matter).
- Their names are a reference to the Arturian Circle, Nimue (the Lady of the Lake who gave Arthur Excalibur), Vivienne (the witch who trapped Merlin inside a tree), and Morgause (as another spelling for Morgan Le Fay).
- The Weird Sisters are based on the three witches of the same name from William Shakespeare's play Macbeth.
- They were also referred to as the Faith Sisters.