I had the audiobook home from the library and unfortunately, it was not the one read by Anthony Head. The narrator I had was also very good but just not good enough to make the story more interesting.
As with some other books by Durbridge, they fall flat when compared to the radio plays. I have no idea if The World of Tim Frazer also originally saw light as a radio play (like the Paul Temple stories), but as a straight narration, the story lacked pace.
It was meant to be a spy story, and indeed much of it reminded me of The Third Man, but ultimately, I gave up caring why the MC's friend disappeared in the first place.