Shen Yubai was an undercover agent and Lu Zhiheng was an anti-narcotics policeman. The two of them worked together to deliver intelligence and destroy drug dealers' dens. Shen Yubai died the day before victory. He never said "I love you" to Lu Zhiheng until he died. He never heard Lu Zhiheng's unspoken love for him until his death.
Mission: Faith is immortal and love lasts forever