"Cat and Mouse" (1974) aka "Mousey" is a very good 70s neo-noir indeed. It's well-paced, well-scripted, well-acted and well-directed. Production values are such that it plays like a regular film and not like a TV-movie. Along the way, I was reminded of the instability of Michael Douglas in "Falling Down" (1993) and that of Chuck Connors in "The Mad Bomber" (1973).
Kirk Douglas is a mousey biology teacher whose life has fallen apart when his wife, Jean Seberg, leaves him for John Vernon, remarrying and taking their son (by another man) with her. The mouse becomes an unstable and unpredictable cat, stalking his ex-wife. The script unfolds this premise very effectively, mainly focusing on each move that Douglas makes. Some are violent, and he's always threatening violence, if not explicitly with scalpels from his biology lab, then implicitly by pressuring Seberg. The story has good balance in showing the counter-moves of Vernon. He hires private detectives to follow Douglas, but he discovers this, leading to his own counter-measures.
As for the noir grounding of this story, years earlier, Douglas married Seberg who was pregnant by another man. He's now obsessed with passing his name on to his son, but Seberg refuses this concession. She's going to remarry, and Douglas goes into emotional turmoil, seeing no rational way forward. His stalking and threats hide some sort of a plan, not even clear to him, but seeming to take shape. The suppressed man has to deny to the world around him that he's a mouse. How can he show that he's a man in a world that places him in a straitjacket of submissive roles? Rebellion is emerging. Order has become confusion. Rationality is now mixed with irrationality. He and we are uncertain how this can end or will end.
The noir scripting and staging of Douglas within the film uses the city environment of Montreal to great advantage, emphasizing his desperation, the ambient pressures of the city, his attempts to avoid detection from prying eyes, his descent into tawdry quarters and his streak of near-madness.