Ever since she could remember, Liu Su was told she had a strange disease where she would die upon seeing the light. With doors and windows nailed shut, she and her brother were trapped for a full eighteen years, living constantly in the guilt of being a burden to their family. One day, mustering the courage to open the curtain, there was nothing unusual about her body at all, and only then did Liu Su realize she had been deceived. When she tried to verify the truth, her mother was already prepared, secretly administering drugs to make her skin fester in public, causing everyone to conclude she had lost her mind. Liu Su secretly tested the medicine residue and found that the ointment contained high concentrations of photosensitizers. Feigning trust in her brother, she set a trap to draw out her mother, and the truth was uncovered.