The Blasphemer, By Nigel Farndale

There is no doubting Nigel Farndale's courage and ambition. The Blasphemer takes the reader from the trenches of the First World War to the "terrorist besieged streets of London"; there is a plane crash, a desperate struggle for survival, angels, academic demons, Mahler and a meditation on the limits of "cold" science when challenged by the "unearthly". Incident and mystery enough to satisfy Dan Brown, but, a novel, the jacket would have us believe, of "rare depth and empathy".

The chief blasphemer in a story that is full of them is the unfortunate Daniel Kennedy, a zoologist and militant atheist, a disciple of Darwin and Dawkins. The plane Daniel and his partner, Nancy, are travelling in crashes into the ocean short of the Galápagos Islands. Desperate for air, he clambers over her to a pocket in the fuselage before diving back into the aircraft to cut her free and help the other passengers. Then he sets out on an epic and selfless swim in search of help.

After hours in the water, close to death from exhaustion and only half conscious, he is encouraged not to give up by an image of a young man beckoning to him. And in an accident of natural selection Darwin would surely have owned miraculous, Daniel's life jacket snags on the shell of a passing turtle and he is pulled to land. The other survivors of the crash are rescued and Daniel is celebrated on television as a hero, but he feels only guilt and shame at the recollection of those first seconds in the drowning aircraft when he scrambled across Nancy to safety.

He is tormented by a sense of his own cowardice, and his ordered view of the world is challenged by the memory of the young man he saw when he was close to death. Was he hallucinating, he wonders, or was it a vision?

Under the post-traumatic strain of it all, his relationship with Nancy begins to disintegrate. If there is a God, he has it in for Daniel: he narrowly escapes a terrorist bombing, his daughter is abducted, and to cap it all, he is diagnosed with a brain tumour.

But the Kennedy family is no stranger to adversity. The parallel narrative tells of Daniel's great grandfather, Andrew, who is led from the mud and death of the battle of Passchendaele by a vision, and into the arms of a French widow.

Farndale endeavours to keep up the pace by bouncing the narrative back and forth between Daniel and his great grandfather. But too often the story loses its way in a no man's land of abstract ponderings on cowardice and the limits of human understanding.

All Daniel's friends have their say – the gay surgeon, a Muslim teacher at his daughter's school, his ludicrously villainous Catholic colleague – without shedding profound light on the existence of a God and angels.