Warning: this is not a Solo for U.N.C.L.E. movie, so get over it.
Former CIA agent Bill Fenner (Robert Vaughn) is now an alcoholic reporter for a wire service, walking through life in the mandatory crumpled suit and trenchcoat. The end of Fenner's career had something to do with his wife, now ex-wife, Sandra Fane (Elke Sommer) working for the KGB, and left Fenner rather cynical towards his old life.
When a conference about nuclear disarmament in Venice ends in a bomb explosion, the CIA pressures Fenner's boss to send him to Venice, for Fenner's former CIA chief Frank Rosenfeld (Edward Asner) knows a few things Fenner will take some time to find out, namely that Sandra is now working for a rather nasty freelance spy named Wahl (Karlheinz Böhm), and had an affair with the US delegate for the conference, which can hardly be mere chance.
But before Fenner stumbles into this particular nest of vipers, he meets Pierre Vaugiroud (Boris Karloff), another freelance operator, but one with a more wholesome agenda. Vaugiroud has written a report that not only confirms that the bomb explosion was caused by a suicide bomb the US delegate of the conference wore, but he also has an explanation for that rather atypical behaviour the film will continue to play coy about. But before Vaugiroud can get his report into the hands of the powers that be, he disappears. Rosenberg sics Fenner to somehow catch his ex-wife and use her to get to the truth of the affair.
Of course, various trusts will be broken and Fenner's cynicism confirmed during the course of the narrative.
TV workhorse director Jerry Thorpe's The Venetian Affair stands in the rather uncomfortable part of the spy movie genre where a film is neither as realistically minded as a Le Carré novel, nor as outright silly as a Eurospy movie or a James Bond film. In honour of what most people on screen apart from Elke Sommer and Karlheinz Böhm are wearing here, I dub this the "trench coats and crumpled suits" sub-genre. We could also call it the "nearly existentialist but not quite" sub-genre. In these films, the spy business is rather dirty, and really not an adventure, but these films aren't generally intellectually or emotionally deep enough to be existentialist about it, nor is there much of a political bone in their bodies.
This doesn't mean that this part of the spy genre isn't worthwhile, it only means you need to bring a different set of expectations to them than you would either take into Eurospyland or into Smiley's office. Otherwise, you end up like the IMDB reviewers complaining this isn't like Solo for U.N.C.L.E. and miss out on a perfectly fine film.
And really, it's difficult to imagine a film with a cast like The Venetian Affair's being a complete loss - Vaughn is expectedly good at looking bitter and somewhat worse for wear, Sommer is ambiguous, Böhm a very polite monster, Asner expertly grumpy, and poor, sick, elderly Boris Karloff gives the poor, sick, elderly spymaster he plays true dignity. Other minor roles are filled out by capable actors like Felicia Farr, Luciana Paluzzi and Roger C. Carmel, so there's nothing at all to complain about on the acting front. Venice is also exceedingly convincing at playing itself with its usual mixture of beauty and decay that seems built for the shady dealings on screen.
Director Thorpe gets the job done in a straightforward yet not completely uncreative way. There's no moment I haven't seen in many other straightforwardly directed films done exactly the same way before, but then this is not the kind of film that needs anything more from a director than the ability to let the plot and the characters go about their business while he takes care of a wee bit of mood building; all this Thorpe does.
That leaves me with The Venetian Affair as a minor yet well enough realized film full of people looking grimly at each other, trench coats, conspiratorial meetings, threatening gestures, and a bit of mind control. I'll take it.