Rebirth: the Sick Neighbor Is Actually a Top Undercover Agent

[Rebirth of the healing forensic heroine ➕The undercover returning sick male protagonist ➕Redemption ➕Criminal investigation, double cleansing HE] Xu Nianan had a neighbor who was terminally ill. She met him several times, and he always had his head lowered, his eyes blocked by the broken hair on his forehead, his face pale and transparent, and he coughed from time to time, as if he would faint in the next second. He never talked to her. Xu Nianan only knew that his name was Qi Yanhan, and they were like the most ordinary strangers. Until—— When Xu Nianan died in the line of duty and his soul left his body, She saw Qi Yanhan rushing over, hugging her who was covered in blood, and cried heartbreakingly. For half a year, her soul followed him, watching him avenge her injustice, crush the darkness alone, and kill all enemies with his own hands. On the day when the last enemy was laid to rest, he came to her tomb again and gently touched the photo on her tombstone, "Without you in this world, life would be less joyful. An'an, I miss you so much." It snowed heavily for seven days, and he leaned on her tombstone and never got up. —— White light swept across, and Xu Nian'an was reborn. He returned to the age of 22. Two years before his murder, no tragedy had happened yet. Qi Yanhan was still in the world, and he was still the mysterious, frail and lonely neighbor who lived next door to her. On the first night of her rebirth, through the thin wall, she could clearly hear the extremely suppressed groan of pain coming from the next door. The tiny sound that she had never paid attention to in her previous life was now heart-wrenching. She realized that she didn't know what disease he was suffering from, but she knew that in this life, she would not let him stand alone in the darkness in a humble and forbearing way. She wanted to heal him and warm him. She knocked on the door opposite without hesitation...