Hot Enough For June is a 1964 British film that was released as Agent 8 3/4 in the US. It's based on a book called The Night Of Wenceslas by Lionel Davidson. I hadn't heard of the book but it's a thriller and I'm not a thriller fancier so it's pretty unlikely I would have read it. I did read the synopsis on the Wikipedia and it seems the book is more serious. The main character is forced into the work, unlike the movie character, who's really tricked into the job. Betty E Box is the producer, Lukas Heller wrote the screenplay and Ralph Thomas directed.
Dirk Bogarde plays a young writer on the dole, he gets a job slip and pops around to a glass company to try not to get a job as a management trainee. Robert Morley is the man in charge and John Le Mesurier is his second in command. Robert offers Dirk a huge salary, it's jumped at and Dirk is hired on the spot. Before he's even been shown to a desk Robert sends him off to Prague that very same afternoon. Dirk has to meet someone at a glass factory but they can't tell him who, there will be a password exchange to ID the guy. Dirk will get a secret message to bring back. Dirk seems a bit dim as he goes along with the highly unlikely story that involves sneaking about behind the Iron Curtain. That's a ding, ding, ding moment to me.
Sylva Koscina plays the government driver that's been assigned to Dirk, they fall for each other. Her father is Leo McKern, he plays the head of the secret police. Everyone is keeping an eye on Dirk and he's the only one who doesn't know he's a spy. When Leo comes to get a confession out of Dirk for being a spy it finally dawns on him and he's a bit surprised. Leo has an offer, confession or a plunge out of his hotel window. Dirk throws things and goes on the run. Eventually he'll get to the British Embassy. There's a bit of a fairy tale ending as Dirk and Sylva head off to the UK arm in arm.
It started off fairly nicely during the getting up to speed part of the story, then it plonked down for a bit of a slog through the streets of Prague part, the last third or so picks up for a bit with a chase and then winds down as they wrap it up. I have a hard time liking a hero who's so easily duped, accidental spy stories have certainly been better. It's still better than average and I would watch it again someday.