This middle section, this flight of fancy — it's impossible to get away from the height metaphors — is a good tale, well-imagined and tenderly realised. But the rest of the book does not subscribe to such simple, outmoded structure. The first section disjointedly tells of three hot air balloon rides taken between 1863 and 1882 and plenty more in between. We glimpse Jules Verne, George Sand, Dumas, Victor Hugo. The world is accelerating and balloons offer a bird's-eye view, previously only allowed to God. "Aeronauts were the new argonauts," says Barnes; although "a balloon brought no evil". He claims that aerial flight cured mankind of the fear of the sin of hubris — of getting above oneself. 

Yet he neglects to take into account the solace of faith, and the importance of remaining grounded (there we go again). In the third section of the book, which is a monologue on grief after his wife Pat Kavanagh's death in 2008, Barnes resists all attempts at kindness or solace. Religion (it need hardly be said, the cornerstone of hope for millennia) is reduced to a witticism, the Holy Trinity naught but the "pale Galilean and his dad". And it is not just cosmic consolation which is rejected. Friends who ask him how he is are insensitive; those who don't are cowardly. "Love is the meeting point of truth and magic," he beautifully puts it. Yet what magic can there be in a coldly logical world? His grief and his humanity are sharply, painfully realised; his humility, less so.

The Orpheus and Euridyce myth, central to modern psychological understanding of the death/depth quandary (being, as it is, practically if not actually a Jungian archetype), is afforded only a mention. "Oh come off it," says Barnes, as though he has never heard the story before. Odd, this, from a book which deals so majestically — despite its brevity — with the cross-pollination of narratives. Barnes writes from the heart; but what an informed, proud, devoted heart he has.