The story of What Happened to Monday is set in a future with limited resources and one-child policies. The sisters, named after the days of the week, try to live secretly. But when one goes missing, chaos ensues and their lives are in danger.
What Happened to Monday tells the story of a group of siblings trying to survive in a restrictive society. They face many challenges and must outsmart the system. Things take a turn when one sister disappears, leading to a thrilling adventure to uncover the truth.