The core of this book is a scholarly study of how Lolita was made.It's clever idea was to notice that Lolita is a road-novel in which Humbert Humbert and Lolita criss-cross America by car and then to ask how Nabokov, a Russian emigre who arrived in the USA in 1940, aged forty, knew the roads. The answer is that Nabokov travelled them and did so primarily in pursuit of butterflies though ostensibly on the way to this or that lecturing job. They were long trips and they absorbed whole summers and Nabokov made copious notes about everything - roads, motels, sky-scapes, landscapes. All the time, he was collecting butterfly specimens for museum collections where he had a paid curatorial role.
Roper makes a fascinating piece of road-scholarship out of this and it only weakens when at the end he throws in a study of Pale Fire and a brief review of Nabokov's later life in Switzerland which could have been left out. In contrast, there is nothing here on Nabokov's role in the making of the first film version of Lolita.
Roper tracks the geographical sources of specific passages in Lolita and does the same for literary sources and antecedents in Nabokov's own writing. He turns up interesting facts such as the information that one of Nabokov's colleagues solved the problem of his own taste for nymphets by marrying a fourteen-year old (there being many more places where this could be legally done circa 1930s - 1940s than there are now). Nabokov duly absorbs the information his colleague volunteers.
I thought this an interesting and worthwhile book. I would have cut the chapters which don't belong and I would have asked for more insight into the extended collaboration between Nabokov and his wife Vera, who agreed with Nabokov that he was a genius and who clearly played a large part in keeping the show on the road, literally and metaphorically - she drove, she took dictation, she wrote lots of the letters needed. But the nature of their relationship remains opaque; perhaps it was essentially banal, like the political positions they occasionally espoused.
Though the book has been adequately proof-read, someone forgot to check the Contents page with results for which that someone ought to win a prize for negligence.
Added 19 May:
I left out what may be the most important thing. In all those road trips across America, Nabokov was not driving. His wife drove or a student hired as a chauffeur drove. Nabokov sat in the passenger seat or the back seat writing. Even in the posed photograph on the front cover of Roper's book, he is not in the driving seat. I need to go back to the book and check if he ever drove at all - maybe did not know how to. It may be important: driving in the 1940s and 1950s was surely marked as a + M masculine characteristic. Nabokov ducks the + M role - and as a result gains writing time.