The conclusion opens in Vanavara as the author learns that he will not get to walk around the site because of wildfires resulting from ever hotter summers. Global environmental threats such as climate change and mass extinctions garner more attention today than menacing objects from space, but an even richer view of the disasters that threated humankind would incorporate unknown nature more fully. The book ends by reflecting on what Tunguska might teach us about the present environmental crisis.