The Ipcress File has all the hallmarks of a great cold-war iron-curtain espionage thriller, except that it's set in London. Michael Caine is Harry Palmer, a counter espionage agent who is investigating the disappearance of some of the country's top scientists. The whole film has a tremendous ambience due to a terrific score by John Barry, sets by Ken Adam and a great washed-out look. Michael Caine is effortlessly brilliant; not the same cheeky character as The Italian Job but never-the-less someone who knows when to go against protocol to get results. Gordon Jackson is good as Palmer's partner as are both Nigel Green and Guy Doleman, Palmer's two superiors.
There are plenty of twists, though not so many to make the plot impregnable; my only issue was that when we found out what the Ipcress File was and what it involved, I didn't feel that it was explained WHY the perpetrators were doing what they were doing. For me that left the end of the film rather flat. Otherwise I was completely engrossed, and completely in love with John Barry's music. but, well, you know, that’s just, like, my opinion man.