Deskmates and Neighbors

On the first day Su Zhihe moved in, Lu Xingci became her deskmate and neighbor. The setting sun stretched his shadow very long, just enough to cover the tips of her toes. She handed over a Band-Aid. He didn't answer, just whispered: "Dirty." During a study trip to Xishan, Su Zhihe discovered a major secret, which appeared on her body and peeled her apart like an onion; What method will Su Zhihe use to find the secret that has lasted for more than ten years? And Lu Xingci accompanied Su Zhihe to unlock the secrets about her