Few recent news items have attracted more attention than the implosion of the Titan submersible. Every aspect of the venture has now been raked over, including the nature of the venture itself. While some were quick to dismiss those on board as obscenely wealthy tourists, others jumped to their defence, declaring them to be bold adventurers pushing the boundaries of human exploration and knowledge. Clearly, exploration is moving from the surface of our planet to the deepest oceans or into space. My musings are prompted by The Library of Lost Horizons, Trevor Hay’s tenth book. During the time of Covid…