The Late Show (1977)

A financially strained, aging private detective named Ira Wells isn't a well man and is barely active in the business. He is a loner who doesn't much care for company or small talk. When his ex-partner Harry Regan, however, shows up at Ira's boarding house one night mortally wounded while on a case, Ira feels it's up to him to get to the bottom of it. The trail leads Ira to a small-time fence named Birdwell, whose young bodyguard Lamar is only too happy to rough up the old man when Ira pays a call. But they make a mistake in intimidating and underestimating Ira, who ends up paying Lamar back in kind as well as tracking down Birdwell's missing wife. Meanwhile, a would-be client named Margo Sperling is introduced to Ira by a mutual acquaintance, Charlie Hatter, a tipster. Margo is a quirky individual who acts as an agent for a singer, sells marijuana on the side and wants to hire Ira to find not a murderer but just her missing cat. As they get to know each other after a rocky start, Ira and Margo hit it off to the point that she offers to become his new partner. But first they need to deal with a dangerous confrontation in Margo's apartment.