The Catalyst is a group of scientific researchers using entertainment as a means of engagement with the public. We believe combining science and theatrical arts is valuable in a variety of ways: • Improvisational skills enable scientists to present their work in an engaging and productive manner, both to communicate new research and to illuminate the process of scientific reasoning for the general public. • Creating new media about current scientific research allows us to bring forth novel science-related narratives and authentic characters from the scientific culture. When scientists lead collaborations with theatre professionals they can connect to the public with emotional nuance while maintaining scientific integrity and highlighting new discoveries. We stage both original and adapted theater with actors who are also practicing scientists, and we host a monthly science-based improv show in the centre of Lausanne: CatCave9. Our English-language weekly improv sessions have become a popular gathering place for scientists interesting in learning theater skills. We continue to hold workshops for public-speaking skills and scientific communication strategies.