Undercurrent Trilogy 3: Abyss Awakening

Deep sea electromagnetic spectrum warfare military thriller. 2028, Qingdao. Lin Yuan's right ear is completely deaf, and he only relies on a bone conduction vocoder engraved with "For those who listen to the sea" to capture the deep sea. Two years later, the 100Hz "Abyssal Language" has never stopped - its grammatical structure is recursive, nesting, and learning to be self-referential. Six monitoring stations around the world received the signal simultaneously: it's not talking to you, it's talking to everyone. Deep in the ruins 6,200 meters below, Hector left notes on the 731st day. The deep sea is no longer silent, it is answering.