Behind the clichéd advice "never judge a book by its cover" is the fact that very often a momentary glimpse of a cover is the only exposure that readers get to a great many books and therefore a striking image and an arresting title can be critical.
It was this combination, spied in a provincial Waterstones, that attracted me to Angelology by Danielle Trussoni. The word itself grabbed me first, followed by a powerful image of an angel in chains on the UK issue from Michael Joseph. And my first judgement was simple and non-negotiable: here was a book I had to read.
Trussoni's story more than matched expectations. Angelology is an enthralling and fascinating novel, combining rigorous forays into theology and religious history with a superb, occasionally heart-stopping thriller that surprises again and again and delights throughout.
Most of us with a Christian upbringing will know something of angels - even if only as the herald of the birth of Christ that visits us each Christmas. Many will know of the war of heaven and the casting out of the dark angels - described in the book of Revelation and given body and style by a great many authors, from Milton to Phillip Pullman and in the crime/mystery genre by John Connolly.
At the heart of the heavenly war story is the fundamental simplicity of the battle between good and evil and the essential mystery of angelic history. A writer of imagination and courage can forge the two into compellin, dramatic stories that linger long in the mind.
Trussoni has these qualities and deploys them triumphantly in Angelology. In her extension of the angelic story, the fallen angels have been incarcerated in a deep Balkan cave system after displeasing God, but their off-spring - the Nephilim, who have both ethereal and human blood - live, with their angelic traits hidden, in the world of men, where they are powerful, wealthy and cruel.
But with their bloodlines "polluted" by centuries of breeding with humans, the Nephilim are in a desperate race to find information about an ancient secret that can restore their vitality and .
Ranged against them are a society of Angelologists, dedicated to the study of angels and protecting mankind from their tyranny.
The story takes place in late 1999 as a scholar - working unwittingly for a Nephilim family - comes close to the source of the coveted information when his research takes him to a convent in upstate New York. In the Milton, Verlaine meets a young nun, Evangeline, and piques her curiosity about wartime correspondence between the former mother superior and the philanthropist Abigail Rockefeller. As the two of them, independently, attempt to discover the nature of the correspondence and the secret it conceals, they unveil the ancient story of the Angelologists and their battle with the Nephilim.
A large part of the story is occupied with the events that preceded the Rockefeller correspondence, taking place in wartime Paris as the Nazis close in and with them the Nephilim desperate to get their hands on the Angelologists' intelligence.
This the book's most atmospheric and powerful passage, but throughout the story-telling is of the highest order balancing the twin demands of exciting narrative with the necessary historical and religious backfill.
I was entranced by it throughout, and delighted to discover that a sequel will follow.
In a summer that looks set to be dominated by vampires, make some time for angels. You will not regret it.