1941, Paris. A family of scientists is on the verge of inventing a powerful, invincible serum. Suddenly, a mysterious force compels them to abandon their young daughter, April. Ten years later, April lives with her beloved cat, Darwin, and continues to delve into her family's research project. Soon, she finds herself entangled in an intricate conspiracy. With Darwin and her most trusted friend, Julius, by her side, she embarks on an adventure to find her parents and uncover the truth behind their mysterious disappearance.