Timing is everything in the movie business. Had British film studio Rank shifted into top gear to adapt the best-selling thriller The Night of Wenceslas by Lionel Davidson soon after its publication in 1960 it would probably have been a completely different film to Hot Enough for June which took four years to reach the screen. Davidson had produced a ground-breaking espionage thriller that had critics reaching for the superlatives and putting him in the same bracket as Graham Greene and Eric Ambler. A film appearing, for example, in 1961 would not have been lost in the box office tsunami, in Britain at least, that greeted Dr No on its movie debut in 1962.
But by the time Hot Enough for June was released a second Bond – From Russia with Love (1963)- had changed public attitudes to spy films and in addition readers were reeling from two blockbuster spy novels, Len Deighton’s The Ipcress File (published in 1962) and John Le Carre’s monumental bestseller The Spy Who Came in from the Cold (published 1963). In preproduction in May 1963, minus any cast, the projected film was still being known as The Night of Wenceslas. Star Dirk Bogarde dithered so much about his involvement that at one point he was replaced by the considerably younger Tom Courtenay (Billy Liar, 1963).

As was often the case in adaptations of best sellers, the screenwriter, in this instance Lukas Heller (Whatever Happened to Baby Jane, 1962) both added to and subtracted from the original material. For example, the Nicholas of the Lionel Davidson novel was not a particularly attractive character, truculent, snippy, with a bad case of self-entitlement, a bit of a ne’er-do-well, scrounging to pay bills, with expensive tastes and far from charming in his relationship with his girlfriend. He is also employed, rather than unemployed and with hankerings to be a writer as in the film, and comes into the orbit of Cunliffe (Robert Morley in the film) who dupes him into thinking an uncle has left him an inheritance.
Sensibly, Lukas Heller dispenses with Nicholas’s back story which posits him as a Czechoslovakian exile, albeit leaving his native land at the age of six, and various other complications concerning that country. He is sent to collect a formula for unbreakable glass. The “hot enough for June” password is a Heller construct and feels as if belongs to an earlier era of spy pictures. In the book all Nicholas has to do is leave his guide book lying around in the factory for the contact to write there the formula. However, rather than discovering he is working for the British Secret Service, the novelist employs a different twist, that the young man is, unknowingly, in the pay of foreigners plotting against Britain.
Davidson envisaged a different kind of Czech girl, more of a Valkyrie, statuesque (“her breasts stood out like bombs”) rather than the slimmer Sylva Koscina. It is Heller who adds the complication of her father heading up the secret police. In the book, her father is merely a musician and conveniently absent for most of the time, freeing up his house for romantic interludes. And the book has none of the James Bondesque features since the first of the series had not been written when The Night of Wenceslas was published.
However, the film having established the alternative world of rival secret agencies, of the girl being under suspicion and of her father being a senior official in the espionage business, the screenwriter then follows the bulk of the novel’s romance and the thrilling episodes involving Nicholas on the run. The swimming pool, cigarette burn, the parade and the milkman can all be found in the book.
There is one element that had to be changed. In the book, Nicholas makes two trips to Prague. But it is a golden rule of screenwriting that a character visits a location only once. Davidson ends his book with a touch of irony: Nicholas is swapped for Cunliffe.
At whose behest, it was decided to insert the comedy is anybody’s guess. Possibly the feeling that the book as written would be too unsophisticated for audiences accustomed to the rattling action and glamour of a James Bond. The Bond-style connections at the beginning of the film are clunky and the later references to espionage at the highest level also seemed to have been slotted in with no regard to retaining the essence of the book.