This case study chronicles the journey of Commonwealth Fusion Systems (CFS) on its ambitious mission to commercialize fusion energy and become the world's leading provider of fusion power plants. Emerging from a "special arrangement" with MIT's Plasma Science and Fusion Center, CFS seeks to revolutionize energy by leveraging high-temperature superconducting (HTS) magnet technology and developing their tokamak fusion machines. Set two years after the company raised $1.8 billion in a record-setting Series B financing, the case explores the technical, financial, and strategic challenges that remain for CFS as it constructs its first demonstration facility and plans for its first commercial power plants.