Watch Online Free on Watchseries. A, the last human on the planet. X, the god, demon, or the future in A's nightmares. In 1972, a futurologist book precisely predicted the human destiny manifested in East Asia. In an unknown era, the last human found a mysterious message from an electronic device and embarks on a quest for a future from the past. In ten chapters, the audience explores this dream-like prophecy.