The first story in the series about Captain Future - a cosmic superhero from the future, a wizard of science and technology, an adventurer and the most implacable crime fighter of all time. Strange and frightening events are happening on Jupiter - Earthlings are exposed to an unknown influence that reverses evolution, and gradually transforms people into their distant ancestors - great apes. Atavism among people is spreading more and more widely, the police and special services cannot cope with this new terrible scourge. The President of the Solar System decides to turn to Captain Future for help, but is the renowned hero able to cope with the nightmare caused by the most dangerous enemy in history? Captain Future vs. Space Emperor, there can't be two winners.