Rosemary Kennedy, the younger sister of US President John F. Kennedy, was left with learning difficulties after birth complications. In 1941, aged 23, she underwent a
lobotomy, a decision made by her father. Immediately following the procedure, her condition worsened and she was institutionalized for the rest of her life. The
libretto of the opera was not written as such, but was assembled from contemporary material including intelligence tests, speeches, family interviews and books. Video projections are used during the opera, described by
The Irish Times as 'compelling'. The title of the opera is taken from a question asked of Rosemary during the opera as part of an intelligence test. A projection is put before Rosemary, and a doctor asks: "Which of these is least like the other?" The projection shows three dogs and a cat. ==Performance history and cast==