Dr. Lena, a marine acoustics expert, spent five whole years tracking a mysterious sound from the deep sea. On a typhoon night, she fell into the ocean, and in the last second before suffocating, a kiss saved her life.The man who saved her is Triton—the 300-year-old king of the deep-sea whales. His people have one rule: falling in love means death. The moment he fell for her, the mark on his collarbone started cracking, and his life entered a three-month countdown.