Spy novel set in the 1960s. I found it a little hard to get into at the beginning, the deliberately awkward conversations in Century House also made for hard reading, and I felt these could have been pruned. That said, it was worth the effort to push through, with an exciting plot with many unexpected twists and a cast of interesting characters (I feel it was no accident that I heard Judi Dench's voice in my head when the character Judith Tench from MI5 was speaking). The author did a good job of staying true to the 1960s. The plot is based around the Prisoner Series, but I have almost no memory of this, so it isn't a precursor for enjoying the book.