You never want to overwork or ham up John le Carré, and director Martin Ritt wisely keeps this 1965 adaptation chilly, subtle, and matter-of-fact. There are parts of it I quibble with, but all in all, this is finely crafted spy story.

I called it a story because both “drama” and “thriller” imply approaches the film never intends to take. It’s not a spy tragedy, either, because that would imply more control over his own destiny, even in error, than poor glum Alec Leamas (Richard Burton) ever achieves. It’s more existentialist than that. It’s an up-close portrait of a profession–and not how that profession grows or changes, but simply how it endures, swapping out operatives as it uses them up. It’s almost like a procedural, but it’s one where you’re not fully invited into the reasoning behind the process–not, at least, until the very end.

Alec Leamas is on the verge of being put out to pasture, and he knows it. He’s been running operatives in East Berlin, but they’re dropping like flies, and now he’s been called back to London. Control (Cyril Cusack) dangles the possibility of a desk job in front of him–the ultimate neutered fate–but eventually tells him it’s not yet time for him to “come in from the cold.” His East German counterpart, Mundt (Peter van Eyck), has to be dealt with first. We then shift, with surprising abruptness, to a prickly, resentful Alec half-settling in to a new life outside of the service. He finds a low-level position cross-referencing books in an occult library, working alongside the idealistic Nan (Claire Bloom), a Communist Party member.

Gradually, it emerges that the purpose of this interlude is to paint Alec as an embittered former agent. Any Soviet eyes on him will see that he’s listless, ill-tempered, and broke, ripe for the pickings. The film chooses to give us an odd level of information for this–we see just enough of his initial meeting with Control to know that something is going on, so discovering the ostensible mission isn’t really a twist, but at the same time, we’re not brought into it, either. We don’t get to follow Alec’s thinking, even at a remove, about how to act in this “post-firing” era. It’s a game for him (if an unfun one), but not for us. But it’s not a trick either. Spending a while at that uneasy level of half-information is thematically appropriate, capturing the tenor of Alec’s peculiar business, but I will shame myself by admitting that I find it just the tiniest bit irritating, too. Only in this instance, though. The film uses this approach much more deftly when Rupert Davies’s Smiley does something against Alec’s wishes long before we know why.

All the uncertainty fits well enough that I would not remotely call it a problem, even when not all of it works for me. What actually is a problem is Nan, who is one of the most unconvincing love interests I’ve seen in quite some time. Nan falls for Alec almost immediately, even though he’s acting surly and ill-tempered. And look, Richard Burton is a very good-looking man, but you would have to be Alain Delon to get a date while being this unpleasant. The movie simply doesn’t have a believable POV for her at all, and it’s worse because there are elements here that could lead to a richer and more human portrayal. The script just doesn’t use them. Nan is here to be pretty and naive and used. She’s not a person, she’s a projection of Alec’s lost innocence and faith in the system. It’s annoying in a classic “this female character is underdeveloped” way, but more than that, it makes the Nan parts of the movie feel false, because this is a movie about manipulating people, and she doesn’t feel like a person. Too often, when she’s on screen, the organic tension grinds to a halt.

Luckily, as Spy moves forward, Nan’s screentime lessens and her role becomes more focused. By the time Alec has officially “defected,” Spy is running like a dream: it’s clever and suspenseful and mildly nauseating all at once. Again, this is, at heart, about intelligence operations, and following the Mundt job from beginning to end is a bitter and believable delight. And though the ending, for me, doesn’t have much emotional impact, it’s perfectly formed and feels like the period that was always going to be on the end of this particular sentence. Smiley and Control would have seen that period coming, this movie makes you think. Alec Leamas doesn’t.

The Spy Who Came in from the Cold is streaming on Pluto and Kanopy.