Secret Partner, The (1961)
This is a terrific little, fast moving crime drama with a noirish feel that was directed by Basil Dearden and stars Stewart Granger. He plays a British shipping company employee that's being blackmailed for his criminal past who finds himself accused of embezzling 135,000 pounds from his employer. All the clues point to his guilt, but a mysterious man (that could be one of several of the film's characters) is responsible. With the police on his tail, estranged from his wife (played by the lovely Haya Harareet, in a femme fatale-like role), Granger's character must fight to prove his innocence before the retiring Detective Superintendent (the always dependable Bernard Lee) catches up with him.
John Brent (Granger) has just learned that his wife Nicole (Harareet) has left him. She picked a bad time too because they're supposed to be hosting a company party in their home very soon. Brent's boss Charles Standish (Hugh Burden) is sorry to hear about his employee's troubles, but since their shipping company president Strakarios (Peter Illing) is coming, and Strakarios’s policy is "happy at home, happy at work", Standish urges Brent to make the best of it. Unfortunately, Nicole arrives unannounced during the party, and everyone in attendance gets wind of their marital troubles. Standish's wife Helen (Melissa Stribling) can't seem to keep her acid tongue from wounding Brent. Other attendees include a "living above his means" interior designer named Lang (John Lee), who'd just done the Brent's flat, and Dr. Alan Richford (Conrad Phillips), a friend of the family who seems a bit too protective of Nicole. It seems Nicole is leaving Brent because she suspects he's having an affair with another woman; after all, how else could he explain the mysterious phone calls and the couple's financial difficulties?
As it turns out, Brent is being blackmailed by an excessive scotch drinker who also happens to be his dentist, Ralph Beldon (Norman Bird). This, and his estrangement from Nicole, makes Brent snap at his secretary (Joy Wood), among others at the office. Beldon is visited by a mysterious, hatted man in a trench coat wearing a stocking over his face. At the point of a gun, this man (who's aware of the blackmailing) "convinces" Beldon to obtain some things from Brent on his next payment visit, providing him with instructions and the necessary tools. He promises to pay the dentist 15,000 pounds for the work. When Brent comes for his normal checkup, Beldon sends his receptionist (Dorothy Gordon) out and tells his patient that he must remove a tooth, necessitating gas. After giving Brent the gas, Beldon administers a shot, ostensibly Pentothal, removes & copies all of Brent's keys, and then questions him to obtain the keys of Standish's office safe. Brent's real name is John Wilson. When Brent comes to, he rubs his hand (where the shot was administered) and says he tastes garlic, which Beldon quickly says is possible from the gas.
The crime is then committed. The mysterious man enters the shipping company offices, drugs the attendant, opens the safe, and makes off with an unusually large payoff (135,000 pounds) because two ships had just come in. Detective Superintendent Frank Hanbury (Lee) and Detective Inspector Tom Henderson (Lee Montague), who will replace him upon his pending retirement, are assigned to the case. Henderson is quick to point out the obvious - it was an inside job. Standish is the first suspect but he has an alibi. Brent, who had just left in his boat on holiday and is the only other person who knew the safe’s combination, is sought. After he is apprehended off the coast of France, the detectives take him to his flat where they discover the tools needed to make copies of keys. Seeing the frame closing tightly around him, Brent lights an all too convenient smoke bomb and flees.
So, it's up to Brent to clear himself; he takes a room in a sleazy hotel (run by Willoughby Goddard's character). He first tries to find the woman named Sandra (encountering Colette Wilde & Paul Stassino) that he'd told the police he'd been with on a drunken night recently, per his marital woes. Meanwhile, Hanbury meets and/or visits Lang, Richford, and Standish, the latter of which was in Nicole's new apartment where the detective finds a fancy & unique piece of jewelry. Though Henderson insists it's "an open and shut case" and that they merely need to find Brent, Hanbury begins to work on different angles. He tells his men to find out who commissioned the jewelry and, later, reveals to Standish that he knows Strakarios was going to promote Brent above him, something that Standish knew that Brent, and Helen, didn't. For himself, Brent visits Standish at the docks (Sidney Vivian is the foreman), Lang's apartment where he speaks briefly with Nicole, and Richford who is shooting target practice in his basement.
*** SPOILERS ***
Eventually, Brent figures it out - that he was "under" in Beldon’s chair longer than he should have been. At this realization, he finds Richford pointing a gun at him. However, he is able to quickly reverse the situation so that the two of them then drop in on Beldon. Brent forces Richford to call Hanbury who comes to hear Beldon, at the point of Brent's gun, confess what happened in the dentist's chair. Hanbury seems satisfied and, later, releases Brent on his own recognizance. Nicole enters her apartment and is temporarily frightened when she finds the mysterious man there. He removes the stocking from his face. It's Brent! He'd gotten Beldon to stop blackmailing him and enough money for a new beginning. However, Nicole is upset. She feels used. She'd just been with Richland, who'd she'd used but had just proclaimed his love for her, and her guilt bothers her. So, they go their separate ways. Brent is called into the retiring Hanbury’s office where he has Beldon’s 15,000 pounds. He asks Brent why he'd commissioned the Neptune (the name of his boat) shaped jewelry for Nicole, given the state of their marriage. Brent says that he was hoping to get his wife back, and is allowed to leave. Hanbury then tells Henderson that Brent did it and Henderson promises to get him. Hanbury then says that "these things seem to work out on their own"; Brent is seen walking on the street with his head down, in despair.