This series got me into Deighton's writing and the genre when I was younger and I love this presentation of the story. I would however disagree with the above comment. From what I have read in the past, it is not Holm's performance that lead Deighton to refuse to have the series released but the butchering that all three books received in the translation to the screen. A great example of this is the rewrite of the boarder crossing that ended Samson's field career. The scene is not in the book, the character who dies in the minefield was never in any of the books and the crossing in Sinker was from East Germany to West Germany, not the Polish frontier. This whole storyline is cloth. The changes in Set similarly damage the integrity of the story. My perspective on Holm's performance was that he portrayed the disorientation of Samson during his wife's defection excellently and I believe comported himself well in portraying the aging field agent desperately trying to bridge the class divide. Samson both pays for his father's idealism and suffers due to its influence on his life. As Clevemore comments, had he gotten himself an education he would have probably been running the department. I think the true loss of performance is due to physical appearance more than anything. Holm is diminutive when compared to the Samson of the book - a physically impressive man capable of using his size to impose a presence.