Encouraging middle school girls to become interested in Computer Science has been a concern in the Computer Science Education community for many years. Although many girls do play digital games, this has not led to further interest in computer science. We believe this is caused by many factors. We are researching the effect of teaching (non-programming) computer science principles embedded in after school games, to encourage girls to study computer science in their future. We maintain that the experience of learning these principles will increase their confidence that they can enjoy learning more about computer science. This on-going NSF sponsored AISL research project is described for discussion.